Long-Term Effects Following an Acute Lateral Ankle

LONG-TERM EFFECTS FOLLOWING AN ACUTE LATERAL ANKLE

SPRAIN IN A COLLEGE-AGED POPULATION

Bethany A. Wisthoff

A dissertation submitted to the Faculty of the University of Delaware in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomechanics and Movement Science

Spring 2019

LONG-TERM EFFECTS FOLLOWING AN ACUTE LATERAL ANKLE

SPRAIN IN A COLLEGE-AGED POPULATION

Bethany A. Wisthoff

Approved: ______Samuel C.K. Lee, Ph.D. Director of the Biomechanics and Movement Science Program

Approved: ______Kathleen S. Matt, Ph.D. Dean of the College of Health Sciences

Approved: ______Douglas Doren, Ph.D. Interim Vice Provost for Graduate and Professional Education

I certify that I have read this dissertation and that in my opinion it meets the academic and professional standard required by the University as a dissertation for the degree of Doctor of Philosophy.

Signed: ______Thomas W. Kaminski, Ph.D. Professor in charge of dissertation

Signed: ______Carrie L. Docherty, Ph.D. Member of dissertation committee

Signed: ______Joseph J. Glutting, Ph.D. Member of dissertation committee

Signed: ______Geoffrey P. Gustavsen, MD Member of dissertation committee

Signed: ______Todd D. Royer, Ph.D. Member of dissertation committee

Signed: ______Charles B. Swanik, Ph.D. Member of dissertation committee

ACKNOWLEDGMENTS

First, I would like to thank my advisor and chair of my committee, Dr. Thomas W. Kaminski, for his never-ending support, advisement, and guidance during my doctoral degree experience. I would also like to thank Dr. Carrie L. Docherty, Dr. Joseph J. Glutting, Dr. Geoffrey P. Gustavsen, Dr. Todd D. Royer, and Dr. Charles B. Swanik for their additional support and for serving on my committee. This study would not have been possible without each of their support and feedback during the study design, subject recruitment, data collection and processing, and writing stages. Next, I would like to thank all of my fellow graduate and undergraduate students who have supported me along the way, especially Victoria Wahlquist and Alissa Strouse, who helped during most of my data collections. I would like to thank all of the student volunteers that I had during my data collections. Additionally, I would like to thank my subjects, the students and the student-athletes, who volunteered to participate in my study and continually showed up to the sessions when asked. Without their dedication and participation, I would not have been able to complete this seminal study.

Lastly, I would like to thank my family, my parents, David and Susan Johnson, and Robert and Barbara Wisthoff, for their continual love and support throughout this process. To my husband, Dr. Michael Wisthoff, for his patience and continual words of encouragement and support. Finally, to my grandparents, whom I’ve lost along the way, but have been my shining light throughout my entire education and life.

v TABLE OF CONTENTS

LIST OF TABLES ...... xi LIST OF FIGURES ...... xiii ABSTRACT ...... xv

Chapter

1 LATERAL ANKLE SPRAINS: A REVIEW OF LITERATURE ...... 1

Epidemiology of Lateral Ankle Sprains ...... 1 Anterior Talofibular Ligament Anatomy ...... 6 Ligament Healing ...... 9 Injury Classification ...... 12 Ankle Joint Laxity ...... 15 Techniques for Detecting Joint Laxity in Chronic Ankle Instability- A Literature Review (Submitted to ATSHC) ...... 23

Abstract ...... 23 Background ...... 23 Literature ...... 26

Stress Ultrasonography ...... 26 Stress Radiography ...... 39 Stress MRI ...... 40

Cost analysis ...... 42 Arthrokinematic Restrictions ...... 44 Dynamic Balance Deficits ...... 47 Chronic Ankle Instability ...... 49

2 TALOFIBULAR INTERVAL FOLLOWING AN ACUTE LATERAL ANKLE SPRAIN ...... 53

Introduction ...... 53 Experimental Design ...... 55 Participants ...... 56 Instrumentation ...... 57 Procedures ...... 58

Demographic and Anthropometric Data ...... 58

vi Injury Classification ...... 58 Weight-Bearing Lunge Test (WBLT) ...... 59 Dorsiflexion Range-of-Motion (DF ROM) ...... 60 Inversion Talofibular Interval (INV TI) ...... 61 Anterior Drawer Talofibular Interval (AD TI) ...... 62

Statistical Analysis ...... 63 Results ...... 64

Injury Classification and Function ...... 64

AAS Over Time ...... 64 Group at 6-months ...... 65 AAS by Severity ...... 65 AAS Over Time Between Ankles ...... 66

WBLT ...... 66

AAS Over Time ...... 66 Group at 6-months ...... 67 AAS by Severity ...... 67 AAS Over Time Between Ankles ...... 67

DFROM ...... 67

AAS Over Time ...... 67 Group at 6-months ...... 68 AAS by Severity ...... 68 AAS Over Time Between Ankles ...... 68

INV TI/ Stress ...... 68

AAS Over Time ...... 68 Group at 6-months ...... 69 AAS by Severity ...... 69 AAS Over Time Between Ankles ...... 69

AD TI/ Stress ...... 69

AAS Over Time ...... 69 Group at 6-months ...... 70 AAS by Severity ...... 70 AAS Over Time Between Ankles ...... 70

Discussion ...... 74

vii Injury Classification ...... 74 WBLT ...... 75 DFROM ...... 76 AD TI/ Stress ...... 76 INV TI/ Stress ...... 77 Conclusion ...... 78

3 THICKNESS OF THE ANTERIOR TALOFIBULAR LIGAMENT FOLLOWING AN ACUTE ANKLE SPRAIN ...... 79

Introduction ...... 79 Experimental Design ...... 81 Participants ...... 81 Instrumentation ...... 82 Procedures ...... 82

Demographic and Anthropometric Data ...... 82 Injury Classification ...... 83 Pain ...... 83 Anterior Talofibular Ligament (ATFL) Thickness ...... 83

Statistical Analysis ...... 85 Results ...... 86

ATFL Thickness ...... 86

AAS Over Time ...... 86 Group at 6-months ...... 86 AAS by Severity ...... 86 AAS Over Time Between Ankles ...... 87

Talar Notch ...... 87 Pain ...... 87

AAS Over Time ...... 87 Group at 6-months ...... 87 AAS by Severity ...... 88

Discussion ...... 90

ATFL Thickness ...... 90 Talar Notch Characteristics ...... 92 Conclusion ...... 94

4 DYNAMIC BALANCE DEFICITS FOLLOWING AN ACUTE LATERAL ANKLE SPRAIN ...... 95

viii Introduction ...... 95 Experimental Design ...... 97 Participants ...... 98 Instrumentation ...... 98 Procedures ...... 99

Demographic and Anthropometric Data ...... 99 Injury Classification ...... 99 Y Balance Test ...... 100 Weight-Bearing Lunge Test ...... 101

Statistical Analysis ...... 102 Results ...... 103

YBT ...... 103

AAS Over Time ...... 103 Group at 6-months ...... 103 AAS by Severity ...... 103 AAS Over Time Between Ankles ...... 104

YBT/WBLT Correlation ...... 104

Discussion ...... 107

YBT ...... 107 Conclusion ...... 109

5 TALOFIBULAR INTERVAL, ATFL THICKNESS, AND DYNAMIC BALANCE ...... 110

Introduction ...... 110 Experimental Design ...... 114 Participants ...... 115 Instrumentation ...... 117 Procedures ...... 118

Demographic and Anthropometric Data ...... 118 Injury Classification ...... 118 Pain ...... 119

Statistical Analysis ...... 119 Results ...... 119

ROM ...... 120 Laxity ...... 120

ix ATFL Thickness ...... 120 Pain ...... 120 Balance ...... 121 Ankle Function ...... 123

Discussion ...... 124

Range-of-Motion ...... 124 Ankle Laxity ...... 125 ATFL Thickness ...... 126 YBT ...... 127 Ankle Function ...... 128 Conclusion ...... 129

6 CONCLUSIONS ...... 130

Limitations ...... 132 Clinical Implications and Future Directions ...... 133

REFERENCES ...... 135

Appendix

A RESULTS FIGURES ...... 147

Chapter 2 Results Figures ...... 147 Chapter 3 Results Figures ...... 151 Chapter 4 Results Figures ...... 153 Chapter 5 Results Figures ...... 155

B INCLUSION QUESTIONNAIRE ...... 164 C FOOT AND ANKLE ABILITY MEASURE (FAAM)- ACTIVITIES OF DAILY LIVING AND SPORTS SUBSCALE ...... 166 D CUMBERLAND ANKLE INSTABILITY TOOL (CAIT) ...... 172 E IDENTIFICATION OF FUNCTIONAL ANKLE INSTABILITY (IDFAI) . 177 F IRB CONSENT FORM & APPROVAL ...... 187

x LIST OF TABLES

Table 1.1: Review of Literature of Detecting Ankle Laxity Using Imaging Methods . 34

Table 1.2: Review of Accuracy and Reliability of Detecting Ankle Laxity Using Imaging Methods...... 38

Table 2.1: Participants Demographics for AAS and CON ...... 57

Table 2.2: Injury Classification for AAS (Grade I-III) ...... 58

Table 2.3: Injury Classification and Ankle Laxity Over Time...... 71

Table 2.4: Injury Classification and Ankle Laxity by Group All Grades at 6- months...... 71

Table 2.5: Injury Classification and Ankle Laxity in AAS by Grade at 24-72 hours. . 72

Table 2.6: Injury Classification and Ankle Laxity in AAS by Grade at 2-4 weeks ..... 72

Table 2.7: Injury Classification and Ankle Laxity in AAS by Grade at 6-months...... 73

Table 3.1: ATFL thickness and Pain in AAS Over Time...... 88

Table 3.2: ATFL thickness and Pain by Group, all Grades at 6-months...... 88

Table 3.3: ATFL thickness and Pain in AAS by Grade at 24-72 hours...... 89

Table 3.4: ATFL thickness and Pain in AAS by Grade at 2-4 weeks...... 89

Table 3.5: ATFL thickness and Pain in AAS by Grade at 6-months...... 89

Table 4.1: Y Balance Test Scores in AAS Over Time...... 104

Table 4.2: Y Balance Test Scores by Group at 6-months ...... 105

Table 4.3: Y Balance Test Scores by Grade at 2-4 weeks...... 105

Table 4.4: Y Balance Test Scores by Grade at 6-months...... 106

Table 5.1: Participant Demographics for Chapter 5 ...... 116

xi Table 5.2: Injury Classification, Ankle Laxity, ATFL Thickness, Pain, and YBT scores by Group at 6-months...... 122

Table 5.3: Subjective Ankle Function Questionnaire Scores by Group at 6-months. 123

xii LIST OF FIGURES

Figure 1.1: Stress vs Strain Curve by Thornton and Bailey...... 12

Figure 2.1: Experimental design for Chapter 2...... 56

Figure 2.2: Figure-of-eight method...... 59

Figure 2.3: Dorsiflexion range of motion ...... 59

Figure 2.4: Position for Weight-Bearing Lunge Test ...... 60

Figure 2.5: Inversion Talofibular Interval ...... 61

Figure 2.6: Musculoskeletal Ultrasound ...... 62

Figure 2.7: Anterior Drawer Talofibular Interval, Static position...... 63

Figure 3.1: Experimental Design for Chapter 3...... 81

Figure 3.2: Position of Musculoskeletal Ultrasound probe over the Anterior Talofibular Ligament...... 84

Figure 3.3: Musculoskeletal Ultrasound Image over the Anterior Talofibular Ligament with Talar Notch...... 85

Figure 4.1: Experimental Design for Chapter 4...... 97

Figure 4.2: Y Balance Test Composite Score (%) Equation...... 99

Figure 4.3: Y Balance Test...... 101

Figure 5.1: Experimental Design for Chapter 5...... 114

Figure A.1: Ankle Girth Over Time in AAS...... 147

Figure A.2: Dorsiflexion Range-of-Motion (DFROM) by Grade (I-III) at 24-72 hours...... 148

Figure A.3: Anterior Drawer (AD)/ Inversion (INV) Stress Over Time in AAS...... 148

xiii Figure A.4: Anterior Drawer (AD)/ Inversion (INV) Stress in AAS vs CON at 6- months...... 149

Figure A.5: Anterior Drawer (AD)/ Inversion (INV) Stress by Grade (I-III) at 24-72 hours...... 150

Figure A.6: Anterior Talofibular Ligament (ATFL) Thickness in AAS vs CON at 6-months...... 151

Figure A.7: Anterior Talofibular Ligament (ATFL) Thickness by Grade Over Time in AAS...... 152

Figure A.8: Y Balance Test (YBT) Scores in AAS Over Time...... 153

Figure A.9: Y Balance Test (YBT) Asymmetry Between Limbs by Group...... 154

Figure A.10: Dorsiflexion Range-of-Motion (DFROM) by Group at 6-months...... 155

Figure A.11: Anterior Drawer (AD)/ Inversion (INV) Stress by Group at 6-months. 156

Figure A.12: Anterior Talofibular Ligament (ATFL) Thickness by Group at 6- months...... 157

Figure A.13: Y Balance Test (YBT) Scores by Group at 6-months...... 158

Figure A.14: Previous Number of Lateral Ankle Sprains by Group...... 159

Figure A.15: Identification of Functional Ankle Instability (IdFAI) by Group at 6- months...... 160

Figure A.16: Cumberland Ankle Instability Tool (CAIT) by Group at 6-months. .... 161

Figure A.17: Foot and Ankle Ability Measure (FAAM)- Activities of Daily Living (ADL) Subscale by Group at 6-months...... 162

Figure A.18: Foot and Ankle Ability Measure (FAAM)- Sport Subscale by Group at 6-months...... 163

xiv ABSTRACT

The ankle is the most common body part injured by an athletic population with ankle sprains consisting of 77% of all ankle injuries. Approximately 72% of patients following an ankle sprain have reported residual symptoms six to 18 months later. Of those that reported residual symptoms, 40% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Previous research has shown that approximately 30% of patients suffering an initial ankle sprain will develop chronic ankle instability. Chronic ankle instability (CAI) is defined by those that have suffered recurrent ankle sprains, may have prolonged symptoms, and may exhibit mechanical and/or functional instability. Functional deficits have been seen in those with CAI, specifically to postural control or dynamic balance. The overall purpose of the current study was to determine if differences existed in the severity of the ankle sprain, pain, and dorsiflexion range-of- motion (DFROM) and the long-term effects of talocrural joint laxity, ligament thickness, and dynamic balance measures after an acute ankle sprain (AAS) in a college-aged population. Secondarily, to determine if differences occur in these measures between AAS, CAI, and to those without a history of ankle sprains (CON). Those who experienced an AAS had increased inversion (INV) stress, INV talofibular interval (TI), and anterior drawer (AD) stress compared to CON and CAI. Anterior talofibular ligament (ATFL) thickness was greater in AAS than CON, and greater in CAI than CON. In DFROM, CAI had less ROM than CON. In the Y Balance Test (YBT), CAI had less relative reach distance in anterior (ANT), posteromedial (PM),

xv and composite (COMP) compared to CON. AAS also had less COMP percentage than CAI and CON. As clinicians, we must be aware that those who sustain a lateral ankle sprain should be assessed in the areas mentioned (range-of-motion, ankle laxity, musculoskeletal ultrasound, dynamic balance) to determine if differences exist over time. This research shows that those that have sustained an AAS, regardless of whether or not they have sprained that ankle before, still show deficits in ankle laxity, ROM, and dynamic balance 6-months later; however, those with CAI continue demonstrating deficits over time.

xvi Chapter 1

LATERAL ANKLE SPRAINS: A REVIEW OF LITERATURE

Epidemiology of Lateral Ankle Sprains

According to a review article by Browne and Barnett1, acute traumatic knee injury and ankle sprains account for the most sport-related acute injuries presented to the emergency department throughout Australia. Shah et al.2 in 2016 reported through a cross-sectional study of the 2010 Nationwide Emergency Department Sample, 225,114 ankle sprains. The authors concluded that females sustained more lateral ankle sprains (57%) than males. Lateral ankle sprains also incurred greater charges than medial ankle sprains ($1008 vs $914). Specifically in an athletic population, Hootman et al.3 summarized 16 years of NCAA injury surveillance data for 15 different sports from 1988-1989 to 2003-2004. This review encompasses 182,000 reported injuries and over one million exposures recorded over that period. The authors defined an exposure as one athlete participating in one practice or game and was expressed as an athlete-exposure (A-E). Over all sports, the injury rates were higher in games than in practices (13.8 vs 4.0 injuries per

1,000 A-Es), with preseason practice injury rates being higher than both in-season and postseason practice rates (6.6 vs 2.3 and 1.4 injuries per 1,000 A-Es respectively). Ankle ligament sprains were the most common injury (15%), overall, of all reported injuries. The highest injury rates were from football for both practices and games (9.6 and 35.9 injuries per 1,000 A-Es respectively).

1 From the 2004-2005 to 2008-2009 athletic seasons, Lievers and Adamic4 obtained injury data from the NCAA injury surveillance system of all foot and ankle injuries reported. The authors focused on incidence of foot and ankle injuries which was 15 per 1,000 A-Es. Eighty percent (80%) of all foot and ankle injuries (3,326) consisted of lateral ankle ligament sprains, syndesmotic sprains, medial ankle ligament sprains, midfoot injuries, and first metatarsophalangeal joint injuries. Lateral ankle ligament sprains were the most common foot and ankle injury, which consisted of a total of 1,498 (45%) with an incidence rate of 6.74 per 10,000 A-Es. The median time loss was six days. Roos et al.5 investigated the injury data during the 2009-2010 to 2014-2015 academic years, where 2,429 lateral ligament complex sprains were reported. Lateral ankle ligament complex sprains occurred at a rate of 4.95 per 10,000 athlete-exposures (AEs) and comprised of 7.3% of all reported injuries to the NCAA Injury Surveillance Program. Sprains to the lateral ankle ligament complex (LLC) was the most commonly reported injury among US collegiate student-athletes. The sports with the highest prevalence of ankle sprains were men’s and women’s basketball (11.96/10,000 AEs and 9.50/10,000 AEs, respectively). Most of these ankle sprains occurred during practice (57.3%) but a higher rate of ankle sprains occurred in competitions than in practices (RR, 3.29; 95% CI, 3.03-3.56). Of the LLC sprains, 11.9% were identified as recurrent injuries, with the most being found within the following sports: women’s basketball (21.1%), women’s outdoor track (21.1%), women’s field hockey (20.0%), and men’s basketball (19.1%). Within this sample of LLC sprains, 44.4% returned to play less than 24 hours from the injury and only 3.6% required more than 21 days before returning to play.

2 When comparing the epidemiological patterns of ankle sprains in youth, high school, and college football athletes, Clifton et al.6 examined injury data from three surveillance programs: Youth Football Safety Study, the National Athletic Treatment, Injury, and Outcomes Network (NATION), and the NCAA injury surveillance program. A total of 124, 897, and 643 ankle sprains were reported in the youth, high school, and college football level, respectively. Due to the increase in activity level and exposures, the ankle sprain rates were 0.59, 0.73, and 1.19 sprains per 1,000 A-Es in each age level, respectively. Interestingly, the number of recurrent ankle sprains were higher in youth football than in high school and college football. The authors concluded that ankle sprain rates were highest in college athletes. Lateral ligament complex sprains were the highest number of ankle ligament injuries at each level (79.0%, 76.6%, and 60.5%, respectively), with youth suffering from lateral ankle sprains more than college athletes. Within a population of NCAA Division-I student-athletes from 37 sports, Hunt et al.7 examined the incidence of foot and ankle injuries over a two-year period. Of all musculoskeletal injuries that were recorded (3861), 27% were foot and ankle injuries where 21% of those (218 of 1035) involved the athlete missing at least 1 day of participation. The average time loss from sport was 12.3 days. Of the 1,035 foot and ankle injuries, 27% were referred to a physician and 84% of these required radiologic imaging. Overall, the injury incidence rate was 3.80 per 1,000 athlete-exposures. The sports with the highest incidence rate were women’s gymnastics, women’s cross- country, women’s soccer, and men’s cross-country. The authors reported that the most frequently reported foot and ankle injuries were ankle ligament injuries, tendinopathies, and bone stress injuries.

3 In a review of ankle injuries and sprains in sports, Fong et al.8 identified 227 studies that reported injuries in 70 sports from 38 counties. The authors concluded that the ankle was the most common injured body site in 34% of the 70 sports. Ankle sprains were the most common ankle injury in 33 of 43 sports (77%), including Australian football, field hockey, handball, orienteering, scooter, squash. In the injuries throughout the countries studied, the ankle was the second most common injured body site after the knee, and the most common type of ankle injury was an ankle sprain. Recently, a systematic review and meta-analysis of prospective epidemiological studies of ankle sprains was published by Doherty et al.9 The number of studies that were included in their analysis was 181 from 144 separate papers with an average rating of 6.67/11, based on the STROBE (Strengthening the Reporting of Observational studies in Epidemiology) guidelines for rating observational studies. Of the included studies, 64% (116) were considered high quality with the remaining studies considered low quality. The authors concluded what has been previously reported, that females have a higher incidence of ankle sprains than males (13.6 vs 6.96 per 1,000 exposures), children compared to adolescents (2.85 vs 1.94 per 1,000 exposures), and adolescents compared to adults (1.94 vs 0.72 exposures). Of all 181 studies, lateral ankle sprains were the most commonly observed type of ankle sprain. In a general clinic-based population, Braun10 found that 72.6% reported residual symptoms six to 18 months after an ankle sprain. Of those that reported residual symptoms, 40.4% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Factors that were associated with moderate to severe symptoms were re-injury of the

4 ankle, activity restriction longer than one week, and limited weight bearing longer than 28 days. van Rijn et al.11 identified in their review, that patients reported a rapid decrease in pain within the first two weeks of injury. One year after an acute lateral ankle sprain, 5% to 33% of patients still experienced pain, while 36% to 85% reported full recovery within a three-year period. The risk of re-sprain that was reported in patients was wide (3% to 34%), with the re-sprain occurring over a period from two weeks to 96 months’ post-injury. A prognostic factor for residual symptoms was identified as training more than three times a week.12 A review of prognostic factors and recovery after an acute lateral ankle sprain was completed by Thompson et al.13 Thirty-six articles were assessed where nine met the inclusion criteria of prospective studies investigating the association between baseline prognostic factors and recover over time. Age, female gender, swelling, restricted range of motion, limited weight bearing ability, pain (at the medial joint line and on weight-bearing dorsi-flexion at 4 weeks, and pain at rest at 3 months), higher injury severity rating, palpation/stress score, non-inversion mechanism injury, lower self-reported recovery, re-sprain within 3 months, MRI determined number of sprained ligaments, severity and bone bruise were found to be independent predictors of poor recovery. The authors concluded that there is insufficient evidence to recommend any specific factor as an independent predictor. A recent longitudinal study by Pourkazemi et al.14 identified predictors of ankle sprain after an index (first) lateral ankle sprain in a prospective cohort of 96, where 10 sustained an ankle sprain. Participants were assessed monthly and number of ankle sprains were recorded over 12 months. Measurements included: demographic measures, perceived ankle instability, ankle joint ligamentous laxity, passive range of

5 ankle motion, balance, proprioception, motor planning and control, and inversion/eversion peak power. Recent index sprain, younger age, greater height and weight, perceived instability, increased laxity, impaired balance, and greater inversion/eversion peak power explained 27 to 56% of the variance in occurrence of ankle sprain (χ2 11,95 = 30.67, p = 0.001). The strongest independent predictors were history of an index sprain (OR = 8.23, 95% CI = 1.66 to 40.72) and younger age (OR= 8.41, 95% CI= 1.48 to 47.96).

Anterior Talofibular Ligament Anatomy The structure, attachment location, and composition of the anterior talofibular ligament (ATFL) is important in relation to ankle sprains, since the ATFL is the weakest and most commonly sprained of the lateral ligament complex. The ATFL average width and length has been previously identified as 7.2 mm and 24.8 mm, respectively.15 The attachment of the ATFL begins on the anterior edge of the fibula, just lateral to the articular cartilage of the lateral malleolus. The average area in the proximal-distal dimension was 8.2 mm and in the medial-lateral direction was 5.4 mm. The center of the ATFL was an average 10.1 mm proximal to the tip of the fibula. The insertion of the ATFL on the talus begins directly distal to the articular surface and the center is on average, 19.1 mm proximal to the subtalar joint. At the attachment on the talus, the average proximal-distal dimension was 8.7 mm and the medial-lateral dimension was 5.6 mm. The position of the ATFL on the dorsolateral aspect of the foot lies 44.8 degrees medially from the fibula toward the talus in the coronal plane.15 Kumai et al.16 examined the pattern of ankle sprains in the ATFL related to its functional anatomy, histology, histopathology, and molecular composition. The authors found the fibular attachment of the ATFL at the point anterior-superior to the

6 tip of the lateral malleolus with the talar end at the border of the lateral articular surface of the talus. The ligament is placed at the entrance of the tarsal tunnel, bracing the talus, and turning around the anterolateral corner of its lateral articular surface. In a histological analysis, much of the ATFL was made up of dense fibrous connective tissue with fibroblasts lying between bundles of collagen fibers. Occasional blood vessels were present with a highly vascular synovial membrane lining its deep surface. The authors concluded that as the ligament comes under strain in the plantar flexed and inverted position, it increasingly bends around the talar articular cartilage, instead of making the accommodation at the insertion site. Recently, Khawaji and Soames17 gave a detailed morphology of the ATFL, specifically for surgical and clinical applications. The length of the ATFL varied from 18.81 mm in dorsiflexion to 21.06 mm in plantar flexion. The middle length width and thickness were 4.97 mm and 1.01 mm respectively. The authors observed one (22.9%), two (56.3%), and three (20.8%) band morphologies of the ATFL, which originated 10.37 mm anterosuperior to the lateral malleolar tip, at an angle of 62 degrees, and inserting 3.92 mm anterior to the anterior lateral malleolar line. The length of the ATFL in neutral was significantly different between males and females (p= 0.008); however, there were no differences between the right and left sides in males and females. There also was a weak correlation between foot length and band number (r= 0.357); however, there was no correlation between foot length and ATFL length (r= 0.243), width (r= 0.151) or thickness (r= 0.112). The number of bands of the ATFL seems to be dependent on sex, males with three and females with two bands; however, the most common number of bands, overall, is two.18

7 Milner & Soames18 identified single, bifurcate, and trifurcate forms of the ATFL, as well. The single and bifurcate forms were noticed bilaterally and unilaterally. The single form (38%) was noticed bilaterally in 8 of the 10. In the bifurcate form (50%), 12 of the 13 were observed bilaterally. The trifurcate form was observed in only three (12%) unilateral ankles in females. The authors could note that the overall width of the ATFL did not appear to vary between the number of bands presenting, thus concluding that the variations to the ATFL do not modify the ligament’s overall function. During ankle joint motion, the ATFL elongates more during plantar flexion and supination and with excessive loading conditions, the ATFL is more vulnerable in plantar flexion and supination. The ATFL elongated from neutral at 16.3 ± 3.0 mm to 20.8 ± 2.7 mm at maximal plantar flexion and shortened from neutral to 13.9 ± 2.9 mm at maximal dorsiflexion. For supination and pronation, the ATFL elongated from neutral to 17.4 ± 3.0 mm at maximal supination and shortened from neutral to 14.8 ± 2.5 at maximal pronation. One thing to consider about these values compared to other studies was the use of MRI. 19 Ozeki et al20 measured the amount of strain changes in the ATFL during a full range of ankle motion. The maximal strain change of the ATFL was 7.9%, where it was elongated in plantar flexion (16.2 degrees) and shortened in dorsiflexion. The authors reported the mean ATFL length in neutral as 19.8 mm. The central fibers of the ATFL functions only in plantar flexion greater than 16 degrees. The authors concluded that the stability of the ATFL should be evaluated clinically while the patient’s foot is in plantar flexion. This study also demonstrated that the lateral ligament complex, including the ATFL, are slack in the neutral position. When an

8 ankle sprain is immobilized in the neutral position, the ruptured ends may contact and keep their original length. In exploring diagnostic imaging of musculoskeletal disorders, Parker et al.21 determined that that substituting musculoskeletal MRI for ultrasound would lead to savings of more than $6.9 billion in the period from 2006 to 2020. The authors used government-published data sets and average costs were determined from government Medicare data from 1996 to 2005. When appropriate, ultrasound can be a cost effective option compared to MRI. Musculoskeletal ultrasound has been used in previous research to detect the thickness at the midpoint of the ATFL in healthy, coper, and unstable ankles. Liu et al.22 examined those differences between injured limb of the coper and unstable group compared to the healthy group. The ATFLs of the injured limb for the coper group

(2.20 ± 0.47 mm, p = .015) and injured limb for the unstable groups (2.28 ± 0.53 mm, p = .015) were thicker than the ATFL of the healthy group (1.95 ± 0.29 mm). The authors concluded that lasting morphologic changes occurred in those with a previous injury to the ankle.

Ligament Healing To understand ligaments, one has to consider what happens when a ligament is injured and how scar tissue forms and the ligament ultimately heals. Ligaments are made up of highly organized, dense, fibrous connective tissue that help to provide stability to joints and assist in joint proprioception. Seventy percent of the ligament is composed of water, with the remaining made up of, 25% collagen, 4% proteoglycans and fibronectin, and 1% cells.23 As Hildebrand and Frank23 elaborate in their article on Scar Formation and Ligament Healing, they describe scar tissue as weak and larger

9 than a normal ligament due to the “increased amount of minor collagens, decreased collagen cross-links and an increased amount of glycosaminoglycans.” Factors that may interrupt the healing of ligaments include the size of gap between the healing ligament ends, the use of motion in a stable joint and the presence of multiple ligamentous injuries. Ligaments are organized with fibers running longitudinally, from insertion point to insertion point; however, fibers may not be parallel from one another. When forces are applied beyond the physiologic range, sequential failure of fibers occur, leading to complete disruption. When ligaments and their scars are pulled to a certain length and held, they may show a decrease in force or stress with time (stress-relaxation). As ligaments provide stability to the joint, when a ligament is removed, the equilibrium of the joint is disturbed. The ability of the joint to function properly will depend on the other structures which may end up taking on more force. Ligaments also contain neuromechanical receptors which provide a reflex loop in order to regulate blood flow, important for inflammation and repair. Ligament healing is similar to wound healing which also ends with the formation of a scar that bridges the torn pieces together. The inflammatory response typically occurs during the first 3- 5 days following an injury. The cells are forming new tissue that will take over as inflammation decreases over the next few weeks. Ligaments are able to withstand biomechanical testing as early as 2-3 weeks following an injury. Remodeling will occur over the next several months and years.23,24 The authors give two comments about ligament healing: 1) even if joint function returns, that does not mean that the ligament is healed 2) a better biomechanical healing environment may be created if other structures can take up the responsibility and protect the healing ligament.23

10 As a ligament heals, its strength becomes compromised which makes it more susceptible to reinjury. The concept of cyclic (fatigue) and static (creep) loading can be seen in ligaments as they heel. This concept is examined through research of the knee ligaments, especially the medical collateral ligament (MCL) of the knee. Even though the MCL is different than the ATFL of the ankle, they both are similar in composition and in that they both are extra-capsular. Thornton and Bailey25 conclude in their 2013 article, that healing ligaments have a shorter lifetime and greater strain rate during fatigue than creep at functional stress ranges (Figure 1.1). The purpose of their study was to investigate the time and strain behavior of ligaments that are healing and have long-term fatigue or creep with stresses in the functional range. Using rabbits, 40 underwent bilateral MCL gap surgeries to section the mid-substance of the MCL. Healing intervals were over a 14 week period, then the hindlimbs were frozen and thawed for mechanical testing. The important findings of this study were: fatigue loading resulted in shorter lifetimes than creep in the healing ligaments and that steady-state strain rate during fatigue was greater than during creep. After a ligament injury, exercises should be closely monitored when performing to functional stresses, using cyclic loading rather than static loading of a healing ligament.

Figure 1.1: Stress vs Strain Curve by Thornton and Bailey.

Recently, Sevick et al.26 examined whether the mechanical properties of reinjured ligaments were similar to injured ligaments using rabbit MCL models. This study categorized the reinjury group into minor (transection) and major (gap) reinjury. Mechanical testing was performed after 5-6 weeks of healing. The transection or minor reinjury and gap reinjury were ‘statistically equivalent’ to transection injured ligaments. Gap reinjury were ‘potentially inferior’ to transection injured ligaments. The differences exhibited between the reinjury ligaments may have been due to the presence or lack of healing properties and the distance between the ligament ends at time of reinjury.

Injury Classification The classification of acute lateral ankle sprains has been previously examined by Malliaropoulos et al.27 in track and field athletes. Over a six-year period, 1,215 injuries were examined with 25% being referred due to an ankle sprain, and 22% were injuries to the lateral ligament complex. The authors included 170 acute lateral ankle

12 ligament injuries with occurred in 148 patients who were examined within 6 hours of the injury. Each ankle sprain was classified 48 hours after the first assessment in the usual fashion, which considered pain, edema, ability to bear weight, active range of motion, and anterior drawer (AD) and talar tilt (TT) tests. A grade I classification had negative AD and TT tests, grade II had positive AD test, and grade III had positive AD and TT tests. Three measurements were taken on both the injured and uninjured sides: active ROM by goniometry, ankle edema with figure-of-eight method, and distance between the posterior articular tip of the tibia to the nearest point of the talus from the AD stress radiographs. At the 48-hour time point after the first 6 hours of injury, 92 (44.2%) patients were classified as having a grade I sprain, 63 (30.3%) as having a grade II sprain, and 53 (25.5%) as having a grade III sprain. Of the 53 grade III ankle sprains, 36 patients had a normal AD radiograph test with a mean difference of 2.19 mm. The remaining 17 patients had a mean difference of 7.41 mm (p < 0.01). The authors divided these two groups into subgroups (IIIA and IIIB). Return to full sport was considered in the IIIA patients with normal AD radiograph tests. These patients returned to unrestricted athletic activity in mean time of 30.22 days. The patients with side-to-side difference greater than 3 mm on AD radiograph test (IIIB) returned to unrestricted athletic activity in mean time of 55.65 days (p < 0.01). Active ROM was also significantly different between the IIIA and IIIB patients. The authors describe the difference between the grade IIIA and grade IIIB as the presence of acute functional and mechanical instability to help plan the management protocol. The injury classifications, proposed by Malliaropoulos et al.,27 includes the following criteria: Grade I- decreased ROM up to 5 degrees compared with the uninjured side and edema up to 0.5 cm; Grade II- decreased ROM more than 5 degrees

13 and less than 10 degrees and edema greater than 0.5 cm and less than 2.0 cm; Grade IIIA- decreased ROM greater than 10 degrees, edema greater than 2.0 cm and normal stress radiographs; Grade IIIB- decreased ROM greater than 10 degrees, edema greater than 2 cm and difference in distance between posterior articular surface of the tibia to the nearest point of talus when comparing uninjured and injured ankles greater than 3 mm. The authors conclude that an initial classification based on clinical criteria, such as clinical tests, pain, and ability to bear weight, is not sufficient for athletes, with the proposed classification limiting residual complaints. Previous work has also assessed ultrasonography images and classified different types of acute ankle ligament injuries by specific characteristics on the images. The authors identified five types: type I by the fibular pattern of the ATFL was intact; type II by swelling of the ATFL and fibular pattern intact; type III by the fibular pattern of the ATFL is disrupted where the ATFL appears swollen and elongation is evident by application of the anterior drawer (elongation sign); type IV by the fibular pattern disrupted where the ATFL tear is complete and unchanged ligament during anterior drawer (floating sign); type V by an avulsion fracture of the edge of the talus or distal lateral malleolus.28 When assessing ankle joint function, swelling, tenderness and bruising may not correlate to recovery in someone suffering from a lateral ankle sprain. Psychological factors such as pain, depression, and fear, may play a role in ones healing as well. Briet et al.29 investigated the correlation between pain or symptoms of depression and ankle specific limitations and pain intensity. The authors used 84 patients with a lateral ankle sprain to complete the Pain Self Efficacy Scale Questionnaire, the Olerud Molander Ankle Score and Ordinal scale of Pain and the Patient Health Questionnaire-

14 2. Greater self-efficacy (p = 0.01) and older age (p < 0.01) were significantly associated with greater ankle specific symptoms and limitations three weeks after the injury and explained 22% of the variability in ankle specific limitations and symptoms.

Ankle Joint Laxity In a systematic review of the functional anatomy, pathomechanics, and pathophysiology of lateral ankle instability, Hertel30 described mechanical instability of the ankle complex as a result of anatomic changes that occur after an initial ankle sprain. He elaborated on the changes that occur as pathologic laxity, impaired arthrokinematics, synovial changes, and potential development of degenerative joint disease. These mechanisms can follow an initial ankle sprain, leading to recurrent ankle injuries and the development of chronic ankle instability (CAI). Hertel proposed the paradigm of mechanical and functional insufficiencies that contribute to the development of CAI and recurrent ankle sprains. Pathologic laxity depends on the amount of ligamentous damage to the specific lateral ankle ligaments. Instability of the talocrural joint is caused by damage to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).31 Damage to the ATFL is commonly assessed manually or by an instrumented stress using the anterior-drawer test, which provides anterior translation of the talus and calcaneus while the tibia and fibula remain stabilized. Damage to the CFL is assessed manually or by an instrumented stress of the talar tilt test, which inverts the rear foot with the talocrural joint in a dorsiflexed position. Hollis et al.32 studied the effect of simulated ankle ligamentous injury on subtalar joint complex laxity. They loaded fresh-frozen cadaveric ankles in inversion-

15 eversion torque to measure rotation and anterior-posterior drawer to measure displacement of the subtalar joint using an MTS testing machine. The ankles were tested in three positions: neutral, 15 degrees of dorsiflexion, and 15 degrees of plantar flexion. Testing was repeated with the anterior talofibular ligament (ATFL) sectioned, then the calcaneofibular ligament (CFL) sectioned. When the ATFL was sectioned, motion increased in dorsiflexion with both anterior-posterior drawer and inversion- eversion torque due to an increase in subtalar motion, which agreed with the results of Rasmussen & Tovborg-Jensen.31,32 Schwarz et al.33 established normative reference values in uninjured ankles for ankle-complex motion using a Hollis Ankle Arthrometer. Women were identified to have greater ankle-complex motion for all variables except for posterior displacement. Total anterior-posterior (AP) displacement of the ankle complex was 18.79 ± 4.1 mm for women and 16.70 ± 4.8 mm for men (p< 0.01). Total inversion-eversion (I-E) rotation of the ankle complex was 42.10 ± 9.0 degrees for women and 34.13 ± 10.1 degrees for men (p< 0.001). Hubbard et al.34 investigated ankle joint laxity in subjects with self-reported functional ankle instability. Subjects were defined as functionally unstable from a FAI questionnaire that Hubbard and Kaminski35 developed. Laxity in the functionally unstable ankle and opposite healthy ankle was determined using stress radiographic and instrumented arthrometer. The portable ankle arthrometer used 125 N of anterior and posterior force and 4 N*m of inversion/eversion torque. Anterior and total AP displacement measured with the arthrometer (12.2 ± 3.1 mm, 19.8 ± 5.1 mm, respectively) and anterior displacement with stress radiography (6.9 ± 2.5 mm) were greater in the FAI ankles when compared to the uninjured ankles (11.1 ± 3.2 mm, 18.3 ± 4.4 mm, 6.2 ± 2.2 mm, respectively).

16 Hubbard and Cordova36 examined the natural recovery of mechanical laxity of the talocrural joint after an ankle sprain over an eight-week period. Subjects with acute ankle sprains were tested three days after injury and at a follow-up eight weeks later. Laxity was measured by anterior and posterior displacement (mm) and inversion and eversion rotation (degrees) by an instrumented arthrometer. This study included lateral ankle sprains that were diagnosed as grade 1 or 2 by the same athletic trainer. A grade 1 ankle sprain was defined as a partial tear of the lateral ligament complex. A grade 2 ankle sprain was defined as decreased motion, some loss of function, torn ATFL, intact CFL, some ligamentous instability (positive anterior drawer), swelling, hemorrhage, and point tenderness. This study reported a significant interaction between group, time, and side for anterior translation (F=4.24, p=.05). There was significantly more anterior displacement at day three (F=19.52, p=.001) and at week eight (F=8.54, p=.010) in the injured group compared to the healthy group. There was also significantly more inversion rotation at day 3 (F=2.70, p=.002) and at week eight (F=5.4, p=.033) in the injured group compared with the healthy group. Hubbard and Cordova concluded that mechanical laxity following an ankle sprain may take longer than eight weeks. Similarly, Hubbard37 examined ligament laxity between subjects with or without unilateral chronic ankle instability (CAI). She found a significant group by side interaction for anterior displacement (F1,30= 370.085, p<0.001) and inversion rotation (F1,30= 7.455, p=0.010), which is comparable to Hubbard and Cordova’s results following an ankle sprain. There was significantly more anterior displacement

(13.35 ± 1.98 mm) and inversion rotation (35.57 ± 2.9 degrees) for the involved ankles of the CAI group than the involved ankles of the stable group (11.8 ± 0.85 mm and

17 32.28 ± 1.82 degrees) and the uninvolved ankles of the CAI group (11.08 ± 1.67 mm and 34.35 ± 2.9 degrees). The inclusion criteria for CAI were previous history of more than one unilateral ankle sprain, frequent giving way of the ankle (at least one per month), feelings of instability, and decreased function (less than 100% on main FADI and less than 95% on sports scale). Additionally, Hubbard administered an ankle injury history questionnaire where they had to answer “yes” to questions 1, 3, 4, 5 and “no” to 6, 7, and 8. Laxity was measured with a portable ankle arthrometer, which has been reported to be a highly reliable (AP: ICC = .98, SEM = .89 mm and IE: ICC = .91, SEM =.98 degrees), and valid tool for measuring ankle ligament stability.34,38 Brown et al.39 concluded, comparatively, that those in the CAI group had increased mechanical laxity in inversion using an instrumented ankle arthrometer (LigMaster) compared to the control group. Intrarater reliability was determined in the study on the arthrometer with the ICC as 0.82-0.90 and standard error of measurement of 2-4 degrees for inversion testing. Inversion stress was completed with a force of 150 N according the manufacturer’s instructions. Even though the CAI group had significantly greater inversion laxity compared to the control group, they did not see any differences between the CAI and coper groups. Overall, the CAI to control comparison had the highest effect size (0.87), with the CAI to coper (0.49) and control to coper (0.39) comparisons at moderate to small, respectively. The authors concluded that mechanical laxity and stiffness may not be contributing factors of individuals developing chronic ankle instability after an initial sprain. Self-reported function was also decreased in the CAI group but not in the coper or control group. Thus, connecting decreased self-reported function and ankle ligament laxity.

18 In a separate analysis by the same authors mentioned previously, Rosen et al.40determined the diagnostic accuracy of instrumented and manual talar tilt tests in a group with different ankle injury history compared with a reference standard of self- report questionnaire, CAIT. Those that were considered to have CAI reported a history of a moderate to severe ankle injury and scored greater than or equal to 26 on the CAIT. Those that were a “coper” reported history of 2 or more lateral ankle sprains on one limb and a CAIT score of greater than or equal to 28. The instrumented talar tilt was completed with the LigMaster arthrometer. The authors established single rater’s reliability on both the manual talar tilt and instrumented arthrometer talar tilt as 0.82- 1.0, SEM = 0.6 and 0.82-0.90, SEM 2-4 degrees, respectively. Sensitivity of LigMaster talar tilt and manual talar tilt was low [0.36 (0.23-0.52), 0.49 (0.34-0.64), respectively]. Specificity of LigMaster talar tilt and manual talar tilt was good to excellent (0.72-0.94, 0.78-0.88, respectively). Positive likelihood ratio (+LR) values were 1.26-6.10 for LigMaster and 2.23-4.14 for manual. Negative likelihood ratio (- LR) values were 0.68-0.89 for LigMaster and 0.58-0.66 for manual. Diagnostic odds ratios ranged from 1.43 to 8.96. The authors concluded that laxity testing to assess CAI with these methods may only be useful to rule in the condition. Docherty and Rybak-Webb41 previously published intrarater reliability as 0.74 for talar inversion with the LigMaster instrumented ankle arthrometer. In the anterior drawer position, intrarater reliability was 0.65. Interrater reliabilities for talar inversion and anterior drawer were 0.76 and 0.81, respectively. The difference between the means for talar inversion over two days was approximately 2 degrees. For the anterior drawer, the difference between the means over two days was less than 1 mm. The

19 authors concluded that both tests are reliable when testing on different days, and with different investigators. When comparing inversion and anterior-drawer measures using an ankle arthrometer to stress ultrasound images, Sisson et al.42 concluded that the ankle arthrometer and ultrasound was not directly correlated when measuring in healthy ankles. This shows that there are differences in the two methods, due to the potential of different patient positions and methods of assessing laxity. The authors also concluded that the ankle arthrometer produced greater anterior displacement, mean difference 5.38mm (95% CI: -3.5 to 12 mm). The percent change in length of the ultrasound in anterior-drawer and inversion were positively correlated (r=.76). Normalized length change values were calculated using the method by Ozeki et al.20, the formulas used gave a percentage of length change (USAD% and USINV%). USAD% = (USAD-USNEUT/USNEUT) x 100. USINV% = (USINV- USNEUT/USNEUT) x 100. Intraclass correlation coefficients (ICC) were calculated using stress ultrasound for neutral (0.77, 95% CI: .42, .91), anterior-drawer (0.91, 95% CI: .78, .97), and inversion (0.91, 95% CI: .71, .96) for interexaminer reliability. Intraexaminer reliability was calculated using stress ultrasound for neutral (0.93, 95% CI: .81, .97), anterior-drawer (0.94, 95% CI: .71, .98), and inversion (0.96, 95% CI: .89, .98). Croy et al.43 showed an increased talofibular interval with anterior-drawer stress in the involved ankle (22.65 ± 3.75 mm, p=.017) compared with the uninvolved ankle (19.45 ± 2.35 mm; limb x position F1,26 = 4.9, p=.035) at baseline (< 7 days from injury). This study also showed greater interval changes in inversion stress in the involved ankle (23.41 ± 2.81 mm) compared with the uninvolved ankle (21.13 ± 2.08

20 mm). A significant reduction in inversion talofibular interval was noted between baseline and week 3 (F1,26 = 5.6, p=0.26). This study was conducted on university students and local community citizens who had recently suffered a lateral ankle sprain, within 14 days from injury, and 3 and 6 weeks from injury. The ultrasound images were performed at the three time points on both the involved and uninvolved ankles with a GE Logiqbook PRO (Westborough, MA) portable US unit using a 38-mm linear array transducer probe operating at 10 MHz and scanning at a depth of 30 mm. Three images were captured in three positions (neutral, anterior-drawer, and inversion). The amount of force used to apply the anterior-drawer and inversion stress was 125 N. Stress radiographs are another common method used to evaluate lateral ankle laxity. A large range has been previously published using this method. Dowling et al.44 aimed to narrow the threshold for diagnosing ankle ligament injury using stress radiography by developing normative values. Anterior drawer and talar tilt stress were completed on 100 ankles with no history of ankle fracture or surgical intervention. Seventy-six ankles were included in their final analysis with the mean anterior drawer of 2.00 ± 1.71 mm and talar tilt of 3.39 ± 2.70°. Similarly, in a second article published by Croy et al.45, the authors identified greater length changes of the anterior talofibular ligament using stress ultrasonography in both coper and CAI groups compared to a control group. Significant length changes were noted in inversion (F2,57=6.5, p=.003) in the coper (20.2% ± 19.6%) and CAI (25.3% ± 15.1%) groups compared with a control group (7.4% ± 12.9%). Significant length changes were also noted in the anterior-drawer (F2,57=6.2, p=.004) in the coper

(14.0% ± 15.9%, p=.016) and CAI (15.6% ± 15.1%, p=.006) groups compared with a

21 control group (1.3% ± 10.7%). CAI group also had lower Foot and Ankle Ability Measure activities of daily living (87.4% ± 13.4%) and sports subscale (74.2% ± 17.8%) compared to the control (98.8% ± 2.9% and 98.9% ± 3.1%; respectively, p<.0001) and coper group (99.4% ± 1.8% and 94.6% ± 8.8%; respectively, p<.0001). In determining the diagnostic accuracy of the anterior-drawer test in assessing anterior talocrural joint laxity in those with a history of lateral ankle sprain, Croy et al.46 identified 53% of subjects had anterior talocrural joint laxity at the reference standard of 2.3 mm or greater and 36% at the reference standard of 3.7 mm or greater. The sensitivity of the anterior-drawer test was 0.74 (95% CI: .58, .86) and 0.83 (95% CI: .64, .93) at the 2.3 mm or greater and 3.7 mm or greater reference standards, respectively. The authors concluded that the anterior-drawer test provides limited quality to detect excessive laxity at the talocrural joint. It is useful when comparing side-to-side in conjunction with other physical exam procedures. One limitation to assessing ankle joint laxity in this population may lie within sex differences and hormone fluctuations. Ericksen and Gribble47 sought to examine the potential hormone contributions to ankle laxity and dynamic postural control during the preovulatory and postovulatory phases of the menstrual cycle using an ankle arthrometer to detect laxity and the Star Excursion Balance Test to detect dynamic balance in healthy women. For anterior-posterior laxity, a side main effect was noted (F 1,38= 10.93, P = .002). For inversion-eversion laxity, a sex main effect was seen (F 1,38= 10.75, P = .002). For the posteromedial reaching task, a sex main effect was demonstrated (F 1,38= 8.72, P = .005). Even though women presented with greater anterior-posterior and inversion-eversion laxity and less dynamic balance, hormone fluctuations did not play a factor in those changes.

22 Techniques for Detecting Joint Laxity in Chronic Ankle Instability- A Literature Review (Submitted to ATSHC)

Abstract Many patients that suffer multiple ankle sprains after the first initial sprain will go on to develop chronic ankle instability (CAI). Those with CAI may have pathologic laxity or mechanical instability from the repetitive damage to the lateral ligamentous structures. Mechanical laxity of the ankle joint has been measured by the clinician with manual stress tests. The purpose of this review is to outline the existing evidence regarding imaging methods of determining ankle joint laxity in those after a lateral ankle sprain, who identify as CAI, coper, and acute. The imaging techniques that are used in research and clinical settings are stress ultrasonography (US), stress radiography, and stress magnetic resonance imaging (MRI). The aim is to identify the specificity, sensitivity, and accuracy of each method and to outline previous research that has used these methods on this population.

Background Ankle sprains are the most common sport-related acute injuries presented to the emergency department.1 The cost incurred in the emergency department was reported as $1,008 per lateral ankle sprain.2 Residual symptoms have been reported in

72% of those that have sustained an ankle sprain six to 18 months post-injury.10 Of those that reported residual symptoms, 40% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Factors that were associated with moderate to severe symptoms were reinjury of the ankle, activity restriction longer than one week, and limited weight

23 bearing longer than 28 days.10 One year after an acute lateral ankle sprain, up to 33% of patients still experienced pain.11 Those that have sprained their ankle but have no residual symptoms are defined as ‘copers’ by using self-assessed disability questionnaires such as the Foot and Ankle Disability Index (FADI).48 A high percentage (70%) of patients that suffer multiple ankle sprains after the first initial sprain will go on to develop chronic ankle instability (CAI).49 Tanen et al.50 identified

23% of a cohort of over 500 high school and collegiate athletes had CAI with half of those having bilateral CAI. Collegiate athletes with CAI suffered more from unilateral

CAI than bilateral (57.6% vs 42.4%). Ultimately, those that develop CAI and continue to have long-term issues may develop post-traumatic ankle osteoarthritis.36,51 In a study by Hintermann et al.51, cartilage damage was noted in 66% of ankles with lateral ligament injuries. Currently, most acute lateral ankle sprains are treated nonoperatively with surgical repair primarily used for patients with chronic and symptomatic ankle joint laxity.52 However, 50% of patients that suffer an ankle sprain do not seek any medical treatment or evaluation.49 It is extremely important for appropriate evaluation, management, and treatment of acute ankle sprains to occur to reduce the possibility of improper healing and decreased function, ultimately leading to CAI. Subjects with CAI and decreased self-reported function have been seen to decrease their step count overall compared to healthy subjects.53 After one single ankle sprain, a significant decrease in physical activity across the lifespan has been seen specifically in mice.54 In older adults with history of sustaining at least one knee or ankle injury a negative impact was observed on physical quality of life.55 If an ankle sprain is mistreated at the onset and the subject develops CAI, short-term deficits in

24 function and activity may be seen which may lead to the potential for long-term health and activity effects.53,56

In a systematic review of the functional anatomy, pathomechanics, and pathophysiology of lateral ankle instability, Hertel30 described mechanical instability of the ankle complex as a result of anatomic changes that occur after an initial ankle sprain. He elaborated on the changes that occur as pathologic laxity, impaired arthrokinematics, synovial changes, and potential development of degenerative joint disease. These mechanisms can follow an initial ankle sprain, leading to recurrent ankle injuries and the development of CAI. Pathologic laxity depends on the amount of ligamentous damage to the specific lateral ankle ligaments, whereby pain, symptoms of “giving-way,” and perceived instability may be associated.

After an initial evaluation of the injury occurs, the clinician will grade the injury (I, II, III) depending upon the severity of the injury and the symptoms presented

(pain, swelling, inability to bear weight, etc.). Instability of the talocrural joint is caused by damage to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL).31 Damage to the ATFL is commonly assessed manually or by an instrumented stress using the anterior-drawer test, which provides anterior translation of the talus and calcaneus while the tibia and fibula remain stabilized. Damage to the

CFL is assessed manually or by an instrumented stress of the talar tilt test, which inverts the rearfoot with the talocrural joint in a dorsiflexed position. Grading, typically, will occur following manual stress tests, such as, the anterior drawer test and talar tilt test. Manual stress tests have been shown to be less reliable in determining stability of the talocrural joint, thus making the clinical decision of injury severity less

25 accurate.40 This can be problematic, since understanding the severity of an ankle sprain plays a significant role in the clinician’s reasoning for specific rehabilitation protocols and time to return-to-play.

In this review, advanced imaging techniques for identifying talocrural joint laxity in those with CAI, coper, or acute will be examined. The purpose of this review is to outline the existing evidence regarding imaging methods of determining ankle joint laxity. The specific techniques that are used in research and clinical settings are stress ultrasonography (US), stress radiography, and stress magnetic resonance imaging (MRI). The aim is to identify the specificity, sensitivity, and accuracy of each method and to outline previous research that has used these methods on this population, as well as, provide clinical recommendations on using these techniques to accurately identify ankle joint laxity in those with previous ankle injuries.

Literature

Stress Ultrasonography

How to Perform

Stress ultrasonography is performed by using a method of stress to the talocrural and subtalar joints of the ankle. Common stress methods use a Telos stress device placing the ankle into an inversion/talar tilt and anterior drawer positions using

150 N of force, or a manual stress provided by the clinician placing the ankle into the talar tilt and anterior drawer tests. Musculoskeletal ultrasound is performed over the

26 ATFL with a probe taking images with a 12 Hz frequency and 1.5 mm depth. Simple measurements can be taken on the ultrasound unit, using the measuring tool, of the length of the ATFL, in millimeters, between the peak of the talus and the peak fibula in a stressed position. These measures have been identified as indicators for CAI and acute injury to have an increased ATFL length in a stressed position. 43,45

Diagnostic Accuracy

In the eight articles that assessed the sensitivity, specificity, and accuracy of stress US. The sensitivity ranged between 74% and 100%.57–64 The articles that were assessed used different methods in determining stress, either with a device like the

Telos, or manually, which may lead us to a larger range between the studies. The specificity of stress US ranged between 38% and 100%, with the majority between

90% and 100%. The accuracy of stress US ranged between 84.2% and 100%. (Table

1.1) In a recent review by Cao et al.65, the authors determined that in diagnosing chronic ankle injuries, US without stress was above 90% for senstivitiy and specificity.

Six articles have used stress ultrasonography, alone or in conjunction with another method, to identify differences in chronically unstable ankles, copers, or those that have sustained acute lateral ankle sprains, compared to healthy uninjured ankles

(Table 1.2).43,45,58,66–68 To assess the stability of the ATFL, stress in two positions were performed: anterior drawer and talar tilt/inversion tests. Subjects in the CAI and/or copers groups demonstrated greater joint laxity in both positions compared to a

27 healthy, uninjured ankle. Those with CAI were included if they have experienced chronic ankle pain or laxity for at least 3 months after the last injury.

As Cai et al.69 showed with their examination of ultrasound images, patients with CAI can be divided into six types based upon their type of injury to the ATFL.

As a clinician, using the ultrasound as a part of our examination process, will be useful in understanding the type and severity of injury our patients may have. Understanding the type of injury will not only help in the rehabilitation process and return-to-play decision, but in our decision making to refer this patient to a physician or specialist early.

Clinical Recommendation

Stress ultrasonography is accurate in detected ankle joint laxity in those with

CAI. However, the limitation to this method is the experience and knowledge of the clinician using the tool. Even though training is required, the overall benefits of identifying the amount of laxity of the joint in patients will aid in the clinicians’ decision making in rehabilitation, time to return-to-play, and time to physician referral.

Research Study Participants Inclusion Criteria Measurements Results Study Design Cheng et Prospective 120 ankles Symptoms present for at Ultrasonography of the Sensitivity = 98.9%, Specificity = al.57 in 120 least 6 weeks complaining ankle prior to surgery 96.2%, and accuracy = 84.2% for patients of lateral ankle pain with or and results compared injury to ATFL and Sensitivity = without swelling and point to operative findings 93.8%, Specificity = 90.9%, and tenderness over the lateral accuracy = 83.3%for injury to CFL. portion of the ankle. 75% CAI in preoperative clinical diagnosis Cho et Retrospecti 28 patients Require surgery with pain Manual anterior drawer Grade 3 lateral instability was 66

29 al. ve or giving way associated test, stress radiography, verified arthroscopically in 100%

with lateral ankle instability MRI, and stress of cases. 78.6% showed grade III resulting in repetitive ultrasound to assess the instability on manual anterior inversion sprains. ATFL prior to surgery drawer test. 86% displayed anterior Conservative treatment translation exceeding 5 mm on failed to alleviate symptoms stress radiography, and 11% talar for at least 3 months. tilt angle exceeding 15 degrees. Lax and wavy ATFL was evident on stress ultrasound in all cases (100%).

Croy et Cohort 25 Suffered a lateral ankle Bilateral stress Talofibular interval increased with al.43 participants sprain within 14 days ultrasound imaging at anterior drawer stress in involved with 27 before the baseline visit and baseline (<7 days), 3 ankle over the uninvolved ankle at acute, agreed to follow-up visits at weeks, 6 weeks from baseline. Inversion stress greater lateral ankle 3 and 6 weeks from injury injury in 3 positions: interval changes in the involved sprains neutral, anterior than the uninvolved ankles. A drawer, and inversion. significant reduction in talofibular Talofibular interval interval between baseline and week (mm) and FAAM-ADL 3 inversion measurements only. and FAAM-sport Croy et Cross- 60 ankles Control: no history of ankle Ligament length Anterior drawer test length changes al.45 sectional (control: injury or no reported ankle change, Anterior greater in CAI and copers n=20, instability. Coper: history of drawer test and end compared to control. Ankle copers: 1 ankle sprain more than 1 range ankle inversion inversion greater ligament-length 30

n=20, CAI: year ago and no residual change in CAI and copers n=20) symptoms of instability of compared to controls. giving way. CAI: reported history of recurrent ankle sprains and reported instability on at least 2 of 5 questions on AII Croy et Prospective, 86 subjects Ankle-injured: history of Talocrural joint laxity 53% of subjects anterior talocrural al.46 blinded, (ankle- lateral ankle sprain from during anterior drawer joint laxity at reference standard of diagnostic- injured: plantar flexion/inversion test (ADT), talofibular 2.3 mm or greater, 36% at 3.7 mm accuracy n=66, movement. Control: free interval or greater. Sensitivity of ADT was control: from any history of ankle 0.74 at 2.3 mm or greater, and 0.83 n=20) injury or reports of at 3.7 mm or greater. Specificity instability was 0.38 and 0.40, respectively. Positive likelihood ratios were 0.66 and 0.41, respectively.

Guillodo Diagnostic 56 CAI After sports-related acute ATFL damage by ATFL damage was detected in 61% et al.59 accuracy patients ankle sprain with symptoms ultrasonography and by ultrasound and 71% by present for at least 3 months computed computed arthrotomography. arthrotomography and Agreement was substantial (K = agreement between the 0.76) for assessing the ATFL. two methods Gün et Prospective, 65 Over 18 years old with Bedside BUS: Sensitivity = 93.8%, al.60 diagnostic- emergency inversion-type ankle injury ultrasonography Specificity = 100%, positive accuracy department (ATFL). ATFL injury was (BUS), X-ray, predictive value = 100%, negative patients defined at sonography when Magnetic Resonance predictive value = 94.3%, and discontinuity of ligament or (MR) imaging of negative likelihood ratio = 0.06%. hypoechoic lesion exists. ATFL injury The diagnostic accuracy of BUS was not statistically different from MR imaging (K = 0.938, P = 31

0.001)

Hua et Prospective, 83 patients Authors did not identify. Ultrasound Accuracy for detection of ATFL al.61 diagnostic- Ultrasound was agreed to examination for injury was 95.2%, sensitivity = accuracy by patients with a diagnosis of ATFL 97.7%, specificity = 92.3%, preoperative diagnosis, injury and subsequent positive predictive value = 93.5%, where 44% had CAI, and ankle arthroscopy for negative predictive value = 97.3%, the remaining had different reference positive likelihood ratio = 12.7, and types of chronic ankle negative likelihood ratio = 0.025 diagnoses with pain. Lee et Prospective 73 patients Chronic ankle pain or laxity Standardized physical Significant difference for ATFL al.70 after remote ankle sprain examination (manual length (ATFL stress) and ATFL which was defined with anterior drawer test), ratio (stress/resting) (p <0.001) symptoms persisting for at stress radiography and between the three groups (Grade I, least 3 months after injury. stress ultrasonography Grade II, Grade III by anterior to assess ATFL drawer test).

Lee and Prospective, 85 patients Physically active adults Point-of-care ankle Ultrasound showed acceptable Yun62 cross- aged 18-40 years with acute ultrasound of ATFL, sensitivity (96.4-100%), specificity sectional ankle sprain, history of CFL, ATiFL, deltoid, (95-100%), and accuracy (96.5- ipsilateral recurrent ankle and Achilles. MRI used 100%). sprain (>3 episodes), ankle as reference standard. instability (anterolateral drawer and talar tilt tests) despite conservative treatment for 6 months, and ankle MRI performed within one month for preoperative evaluation. Mizrahi Prospective/ 54 patients Asymptomatic: no history Sonography of the Significant increase in mean et al.68 Retrospecti (asymptoma of a sprain, other trauma, or ATFL to determine change in ATFL length (laxity) in 32

ve tic: n=20, surgery to either ankle. length in neutral and the symptomatic group (1.26mm, symptomati Symptomatic: Clinically manual inversion stress P<.0001). c: n=34) evaluated and diagnosed positions with CAI from history and physical examination by foot and ankle surgeons. Oae et Prospective, 34 patients Consecutive patients who Stress radiography (X- 88% showed ATFL injury in the al.63 diagnostic- needed an operation due to P), ultrasound (US), arthroscopy. The diagnosis of accuracy severe problems, except Magnetic Resonance ATFL injury with stress X-P, US, fractures. Acute or chronic (MR) imaging, and MR imaging were with an accuracy injury was identified. arthroscopy for of 67%, 91%, and 97%, comparison to respectively. US and MR imaging determine accuracy of had the same location of injury as ATFL injury detection arthroscopy in 63% and 93%, respectively.

van Dijk Prospective 160 patients Ages 18 to 40 years of age Physical examination Ultrasound used alone showed 92% et al.64 presented to emergency within 2 days and 5 sensitivity, 64% specificity, and department within 2 days days after inversion cost $111. Stress radiographs used after acute inversion injury trauma, arthrography, alone showed 68% sensitivity, 71% of the ankle stress radiography, and specificity, and cost $78. Numbers ultrasonography decreased when physical exam took place < 48 hours from injury but increased when included with the physical exam 5 days after injury. Hubbard Cohort 51 subjects Self-reported unilateral Ankle-subtalar joint Arthrometry of anterior and total et al.36 functional ankle instability motion for total AP displacement and radiography (FAI) answering "yes" to anteroposterior (AP) of anterior displacement were specific questions on the 11 displacement and total greater (p < 0.05) in the FAI ankles 33

question questionnaire inversion-eversion when compared with uninjured rotation using an ankles instrumented ankle arthrometer. Anterior and lateral stress for anterior displacement and talar tilt using stress radiographs. Dowling Cohort 46 No history of ankle fracture Stress radiography of Mean anterior drawer 2.0 ± 1.7 mm et al.44 participants or surgery for ankle anterior drawer test and and talar tilt 3.4°± 2.7° in the (76 ankles) instability or history of talar tilt test normal ankle. previous ankle sprain

Lee et Prospective 66 patients Combined ATFL and CFP Bilateral manual stress Ankle stress radiographic al.67 cohort injury radiographs. Anterior intraobserver and interobserver talar translation (mm), agreement was ICC = 0.91 and talar tilt (°), and talar 0.82 for talar rotation, ICC = 0.64 rotation (%) in injured and 0.51 for anterior talar vs uninjured ankles. translation, and ICC = 0.78 and Intraobserver and 0.71 for talar tilt angle, interobserver reliability respectively. was measured Seebauer Prospective 50 subjects 18 years and older and Inversion and anterior Significant differences between et al.72 pilot (72 stable either symptomatic drawer test performed groups A and B (p < 0.05) were ankles in 37 instability of the ankle joint under 4 views using found in talar tilt, subtalar tilt, subjects, 28 for inclusion in instability MR imaging to assess anterior talus translation, anterior ankles in 15 group (B) or absence of talar tilt, subtalar tilt, calcaneus translation, medial 34

subjects pathologic findings in the anterior talus talocalcaneal translation, and with CAI) ankle for inclusion in translation, anterior decrease in diameters of CFL and control group (A). calcaneus translation, PTFL. medial talocalcaneal translation, and diameters of lateral ankle ligaments Table 1.1: Review of Literature of Detecting Ankle Laxity Using Imaging Methods. (ATFL= anterior talofibular ligament, CFL= calcaneofibular ligament, PTFL= posterior talofibular ligament, CAI= chronic ankle instability, mm= millimeters, FAAM= Foot and Ankle Ability Measure, ICC= interclass correlation coefficient

Research Study Design Participants Inclusion Criteria Measurements Results Study Cheng et Prospective 120 ankles in Symptoms present for at Ultrasonography of the ankle Sensitivity = 98.9%, al.57 120 patients least 6 weeks complaining of prior to surgery and results Specificity = 96.2%, and lateral ankle pain with or compared to operative accuracy = 84.2% for without swelling and point findings injury to ATFL and tenderness over the lateral Sensitivity = 93.8%, ankle. 75% CAI in Specificity = 90.9%, and preoperative clinical accuracy = 83.3%for diagnosis injury to CFL. Croy et Prospective, 86 subjects Ankle-injured: history of Talocrural joint laxity during 53% of subjects anterior 46

35 al. blinded, (ankle- lateral ankle sprain from anterior drawer test (ADT), talocrural joint laxity at

diagnostic- injured: plantar flexion/inversion talofibular interval using reference standard of 2.3 accuracy n=66, movement. Control: free stress ultrasonography mm or greater, 36% at 3.7 control: from any history of ankle mm or greater. Sensitivity n=20) injury or reports of instability of ADT was 0.74 at 2.3 mm or greater, and 0.83 at 3.7 mm or greater. Specificity was 0.38 and 0.40, respectively. Positive likelihood ratios were 0.66 and 0.41, respectively.

Guillodo Diagnostic 56 CAI After sports-related acute ATFL damage by ATFL damage was et al.59 accuracy patients ankle sprain with symptoms ultrasonography and detected in 61% by present for at least 3 months computed arthrotomography ultrasound and 71% by and agreement between the computed two methods arthrotomography. Agreement was substantial (K = 0.76) for assessing the ATFL. Gün et Prospective, 65 Over 18 years old with Bedside ultrasonography BUS: Sensitivity = 93.8%, al.60 diagnostic- emergency inversion-type ankle injury (BUS), X-ray, Magnetic Specificity = 100%, accuracy department (ATFL). ATFL injury was Resonance (MR) imaging of positive predictive value = patients defined at sonography when ATFL injury 100%, negative predictive discontinuity of ligament or value = 94.3%, and hypoechoic lesion exists. negative likelihood ratio = 36

0.06%. The diagnostic accuracy of BUS was not statistically different from MR imaging (K = 0.938, P = 0.001) Hua et Prospective, 83 patients Authors did not identify. Ultrasound examination for Accuracy for detection of al.61 diagnostic- Ultrasound was agreed to by diagnosis of ATFL injury ATFL injury was 95.2%, accuracy patients with a preoperative and subsequent ankle sensitivity = 97.7%, diagnosis, where 44% had arthroscopy for reference specificity = 92.3%, CAI, and the remaining had positive predictive value = different types of chronic 93.5%, negative predictive ankle diagnoses with pain. value = 97.3%, positive likelihood ratio = 12.7, and negative likelihood ratio = 0.025

Lee and Prospective, 85 patients Physically active adults aged Point-of-care ankle Ultrasound showed Yun62 cross- 18-40 years with acute ankle ultrasound of ATFL, CFL, acceptable sensitivity sectional sprain, history of ipsilateral ATiFL, deltoid, and (96.4-100%), specificity recurrent ankle sprain (>3 Achilles. MRI used as (95-100%), and accuracy episodes), ankle instability reference standard. (96.5-100%). (anterolateral drawer and talar tilt tests) despite conservative treatment for 6 months, and ankle MRI performed within one month for preoperative evaluation. Oae et Prospective, 34 patients Consecutive patients who Stress radiography (X-P), 88% showed ATFL injury al.63 diagnostic- needed an operation due to ultrasound (US), Magnetic in the arthroscopy. The accuracy severe problems, except Resonance (MR) imaging, diagnosis of ATFL injury 37

fractures. Acute or chronic and arthroscopy for with stress X-P, US, MR injury was identified. comparison to determine imaging were with an accuracy of ATFL injury accuracy of 67%, 91%, and detection 97%, respectively. US and MR imaging had the same location of injury as arthroscopy in 63% and 93%, respectively.

van Dijk Prospective 160 patients Ages 18 to 40 years of age Physical examination within Ultrasound used alone et al.64 presented to emergency 2 days and 5 days after showed 92% sensitivity, department within 2 days inversion trauma, 64% specificity, and cost after acute inversion injury arthrography, stress $111. Stress radiographs of the ankle radiography, and used alone showed 68% ultrasonography sensitivity, 71% specificity, and cost $78. Numbers decreased when physical exam took place < 48 hours from injury but increased when included with the physical exam 5 days after injury. Lee et Prospective 66 patients Combined ATFL and CFP Bilateral manual stress Ankle stress radiographic

38 67

al. cohort injury radiographs. Anterior talar intraobserver and translation (mm), talar tilt interobserver agreement (°), and talar rotation (%) in was ICC = 0.91 and 0.82 injured vs uninjured ankles. for talar rotation, ICC = Intraobserver and 0.64 and 0.51 for anterior interobserver reliability was talar translation, and ICC = measured 0.78 and 0.71 for talar tilt angle, respectively.

Table 1.2: Review of Accuracy and Reliability of Detecting Ankle Laxity Using Imaging Methods. (ATFL= anterior talofibular ligament, CFL= calcaneofibular ligament, PTFL= posterior talofibular ligament, CAI= chronic ankle instability, mm= millimeters, FAAM= Foot and Ankle Ability Measure, ICC= interclass correlation coefficient, °= degrees, %= percentage)

Stress Radiography

How to Perform

Like stress ultrasonography, the stress is performed manually or by a Telos stress device in the inversion/talar tilt and anterior drawer positions while a radiograph is completed. The stress and radiographs are performed separately by experienced radiologists and clinicians. Static and stressed radiographs would be taken to determine the translation or ankle joint laxity. Multiple views with a radiograph are necessary in order to view the inversion/talar tilt and anterior drawer positions.

Precautions must be taken for the patients involved in radiographs due to radiation exposure. Unlike ultrasonography, radiography can help our understanding of bone positioning during these stressed positions. Understanding the position of the talus, for example, may be important in those with CAI as Wikstrom and Hubbard71 noted that the talus is positioned significantly more anterior without stress in involved CAI limb than uninvolved CAI limb, in turn, limiting ankle dorsiflexion.

Diagnostic Accuracy

Two studies assessed these areas for stress radiography, where the sensitivity was 68%, specificity was 71%, and accuracy was 67%.63,64 Lee et al.70 used bilateral manual stress radiographs and found the reliability of this measure in detecting ankle joint laxity in a combined ATFL and CFL injury ranged from ICC= 0.51 to 0.91 for interobserver and intraobserver agreement in talar rotation and anterior talar

39 translation. (Table 1.1) Stress radiography was examined in four articles and saw the same increase in ankle joint laxity in both positions for those designated as CAI, coper, or acute.44,66,67,73 (Table 1.2) Cho et al.66 showed that stress radiography detected a greater percentage of instability during anterior translation than on a manual anterior drawer test.

Clinical Recommendation

Stress radiography can be used to detect ankle joint laxity in those with CAI, coper, or acute; however, it has not been used as widely in this population. As for its sensitivity, specificity, and accuracy, there may be a better alternative that may cost less time and money. This method may be a better option for a patient that may have a suspected talar position deviation, which would be difficult to detect on an ultrasound.

Stress MRI

How to Perform

1-T open high-field-strength MRI system (Panorama HFO, Philips Healthcare) is the MRI system previously used by Seebauer et al.72 Coronal, axial, and 45 degree paraxial T2-weighted fast spin-echo images were used for the inversion stress test and sagittal images were used for the anterior drawer test. Inversion/talar tilt stress images were measured with two independent tangent lines by an experienced radiologist: (1) inferior articular surface of the tibia (2) most proximal talar contour. Subtalar tilt was also measured using the angle between the talus and the calcaneus in the lower ankle joint. In the sagittal plane images, anterior talus translation was measured as the

40 shortest distance between posterior lip of distal tibial joint surface and talar dome.

Anterior calcaneus translation was also measured as the distance from upper posterior aspect of the calcaneus to inferior head of the talus.

Diagnostic Accuracy

Only one study, to my knowledge, has used a novel stress device during an

MRI this population. (Table 1.1) The authors determined the accuracy of this method to be 97%. In subjects with CAI and healthy, uninjured subjects, they found significant differences in the two groups in talar tilt, subtalar tilt, anterior talus translation, anterior calcaneus translation, medial talocalcaneal translation, and decrease in diameters of CFL and PTFL.72

Clinical Recommendation

Measurement of subtalar joint laxity is important in assessing the stability of the lower ankle joint, especially when considering multiple planes using MRI. Stress

MRI offers clear images in the evaluation of mechanically unstable ankles and offers simultaneous comparison with the upper ankle joint. 72 Even though, to date, there has only been one study completed using MRI, this method is accurate in detecting laxity of the ankle joint. Ultimately, the cost and time it would take to complete this evaluation on one patient would be warranted in certain circumstances that require information about the translation of the joint in those two positions.

Cost analysis

Overall, each method is accurate in detecting ankle joint laxity in those with

CAI, copers, or acute injuries; however, the accessibility and cost of each of these methods must be considered. Both radiograph and MRI methods must be administered by a lab technician or specialist as training is needed to correctly implement.

Ultrasound can be easily administered by a clinician and utilized daily without having to the leave the clinic. Ultrasound is also less invasive than radiographs and MRI.

Each method has its own set of costs associated with using these techniques.

According to Feger et al.74, the average cost for a complete ankle X-ray is $78 and

$1,055 for MRI per visit/treatment in the United States. Ultrasound has been noted to cost $111 per visit/treatment.64 Ultrasound provides advantages to clinicians, such as, dynamic imaging with immediate feedback, noninvasiveness, lower overall cost limiting the number of repeated visits, and quicker scan times. However, a down side of ultrasound in the evaluation of the lateral ankle ligaments is that it is highly operator dependent. The operator must understand the scanning technique, potential pitfalls, and how the recognize a normal vs injured ligament.75

CONCLUSIONS

Stress US, radiography, and MRI are all accurate measures in detecting ankle joint laxity in those with CAI, copers, and acute sprains. Stress ultrasonography has the highest reported accuracy of the three measures and is one of the lower cost options after an ultrasound unit is purchased. This method is best used on patients who have chronic symptoms, such as, repetitive sprains, pain, and swelling, to determine

42 ankle joint laxity and thickness of the ATFL. Stress radiography has moderate accuracy compared to ultrasonography and MRI. This method may be best used when available for patients with CAI that may have a talar position deviation to detect without stress. Stress MRI, as Seebauer et al. described, is a reliable method at 97%72; however, it is most cost prohibitive and least used in a CAI population in research.

Even though there is no consensus on a gold standard for imaging of detecting ankle joint laxity in current research, stress US is the most commonly used, recently, with radiograph and MRI less commonly used due to cost, radiation exposure, and limited of access and training using the equipment.

In the future, these techniques for detecting ankle joint laxity in those with CAI should be implemented to detect the need for further intervention. Utilizing these techniques can assist clinicians in educating patients and giving them immediate feedback on their current condition. Having access to at least one of these methods has the potential to offer immediate feedback and assist in communication to the entire medical team regarding the diagnosis and treatment process.

Arthrokinematic Restrictions After an ankle sprain, range of motion is reduced in dorsiflexion compared to the healthy ankle and has been identified as a strong injury predictor.76 This can result from an anterior displacement of the talus or loss of posterior talar glide.77 Previous research has found evidence that dorsiflexion range of motion predicts future lateral ankle sprain.76,78–80 Those with reduced dorsiflexion range of motion (34 degrees) are approximately five times more likely to suffer an ankle sprain compared to those with average range (45 degrees).78 The amount of range of motion or arthrokinematic restriction that occurs at the ankle will depend on the severity of the ankle sprain. During gait, restriction of dorsiflexion range of motion (ROM) may increase the risk of ankle sprains limiting the ankle’s ability to reach a ‘closed-packed’ position during midstance.81 For normal walking, at least 10 degrees of dorsiflexion is required; however, for running, 20 to 30 degrees of dorsiflexion is required.82 In a jump landing, those with dorsiflexion ROM restriction have less knee flexion and greater ground reaction forces.83 The measurement of DF ROM, most accurately, is done in a weight-bearing position since the ankle is in a functional, “closed-packed” position. The weight- bearing lunge test (WBLT) has been previously identified as the best measure of DF ROM compared to non-weight bearing goniometric measurements.84 Bennell et al.85 have previously reported the intra-rater ICC ranging from 0.97 to 0.98 and the interrater ICC as 0.97 (using an inclinometer) and 0.99 (using distance from the wall in cm). Previous research has identified the causal relationship between dynamic balance tasks and DF ROM.86–89 In those with CAI, decreased DF ROM and anterior Star Excursion Balance Test (SEBT) reach distance has been seen compared to healthy controls.87 A fair positive correlation has been reported between DF ROM and the

anterior reach direction (r=.55), posterolateral reach direction (r=.29), and composite SEBT scores (r=.30). Ankle DF ROM can influence dynamic balance measures, especially in the anterior reach.89 The difference between ones WBLT performance in each limb has been reported as asymmetry by previous researchers. In determining normative values for asymmetry in healthy adults, Hoch and McKeon90 examined bilateral symmetry and using determinants of age, height, mass, leg length, foot length, and posterior displacement of the ankle-subtalar-joint-complex as influencing WBLT performance. The WBLT was performed using the knee-to-wall technique used by Larsen et al.91 and methods first performed by Bennell et al.85 Larsen et al. 91 found inter-tester reliability of WBLT was high, with an ICC of 0.984 (95%CI: 0.963-0.993). The ICC for Tester A was 0.989 (95%CI: 0.974-0.995) and Tester B was 0.990 (95%CI: 0.977- 0.996). Posterior displacement was measured using an instrumented arthrometer.

Posterior ankle-subtalar-joint-complex displacement was 5.21 ± 2.27 mm and 5.46 ± 1.69 mm for the left and right ankles, respectively. For the right limb, Pearson-product moment correlations revealed no significant relationships between WBLT performance and age, height, mass, right leg length, right foot length, or right posterior talar displacement (All P’s > 0.17). For the left limb, Pearson-product moment correlations revealed no significant relationships between WBLT performance and age, height, mass, left leg length, left foot length, or left posterior talar displacement (All P’s > 0.10). The authors concluded that, with an asymmetry between limbs in the WBLT of 1.5 cm or less (68%) with a maximum of 3 cm and a level of agreement of 1

mm, no limb bias existed. These differences observed may be true between-limb differences instead of measurement error. Powden et al.92 completed a systematic review of the reliability and minimal detectable change of the WBLT. Pubmed and EBSCO Host databases were used from inception to September 2014 with the Quality Appraisal of Reliability Studies assessment tool was used to determine the qualities of included studies. Of the 12 studies included, there was strong evidence that intra-clinician reliability (ICC = .65- .99) and inter-reliability (ICC = .80-.99). Average MDC scores of 4.6 degrees or 1.6 cm for inter-clinician and 4.7 degrees or 1.9 cm for intra-clinician. Langarika-Rocafort et al.93 completed an intra-observer reliability and agreement five measurements of dorsiflexion during the WBLT and assessed the degree of agreement between three methods in female athletes. Twenty-five volleyball players were used to evaluate dorsiflexion using five methods: heel-wall distance, first toe-wall distance, inclinometer at tibia, inclinometer at Achilles tendon, and the dorsiflexion angle obtained by a simple trigonometric function. The inclinometer had more than 6° of measurement error while the angle calculated by trigonometric function had 3.28° error. The reliability of inclinometer based methods had ICC < 0.90 with a distance based method and trigonometric angle measurement had ICC > 0.90. Howe et al.94 compared the methods of WBLT described by Bennell et al.85, Konor et al.84, and Langarika-Rocafort et al.93 to provide normative data in a healthy population. Konor’s methods seemed to have the greatest difference in normative values compared to Bennell and Langarika-Rocafort, especially in the toe-to-wall distance (9.5 ± 3.1 cm vs 13.8 ± 3.7 cm vs 13.4 ± 3.1 cm, respectively).

Dynamic Balance Deficits Dynamic balance deficits have been noted in those with functional instability and are associated with the amount of time in balance and the number of foot lifts.95 The Y Balance Test (YBT), which was developed by Functional Movement Systems96 and described by Plisky et al.97, is a reliable dynamic balance assessment tool involving the participant to maintain single-limb balance while sliding an indicator with the opposite limb. Butler et al. identified a cut-off point of 89.6% for the composite score on the YBT with a sensitivity of 100% and specificity of 71.7%. Within that study, a college football player who scored below 89.6% was 3.5 times more likely to obtain a noncontact lower extremity injury.98 Female athletes that score

<94% of their limb length are 6.5 times as likely to sustain a musculoskeletal injury. It is important to note that previous research has tested on a specific sport populations, such as football and basketball.98,99 Asymmetry in the reach distances have been investigated previously.100,101 In the anterior reach, an observable difference > 4 cm between the limbs is associated with an elevated risk of injury.99 Female athletes have demonstrated less asymmetry than male athletes in the anterior reach direction (t188 =-

1.920, P = .02),, specifically, but they were similar in the posteromedial (t188= -1.529,

P = .13) and posterolateral (t188 = 0.322, P = .75) directions. The MCID for the YBT composite score has been previously reported as 3.5%, relative to limb length.101,102

Even though current research focuses heavily on the anterior reach as a risk factor, de Noronha et al. found that subjects with better posterolateral performance on the SEBT were less likely to suffer an ankle sprain (HR 0.96, 95% CI: 0.92-0.99).79 Optimal cut- off scores were noted as 2, 9, and 3 cm for anterior, posteromedial, and posterolateral reach, respectively. However, no cutoff score has been identified for asymmetry in composite scores to be associated with an increased rate of injury.98,103 Previous

research has been conflicted about the utility of the YBT in predicting subsequent injury, but it is not meant to be the only injury risk assessment tool that should be used. It is also important to note the association of limb dominance in our dynamic balance measures. The relationship between limb dominance and ankle sprains have been investigated with mixed results.104 Beynnon et al. found that limb dominance was unrelated to the risk of ankle injury in a population of male and female soccer and lacrosse athletes and female field hockey athletes.105 Conversely, Willems et al. concluded that 80% of ankle sprains occurred on the dominant limb.106 Their findings support Ekstrand and Gillquist, who found 92% of ankle injuries affected the dominant limb in soccer athletes.107 Schwiertz et al.102 examined test-retest reliability of the YBT in 178 healthy adolescents from 11-19 years old. The YBT was performed twice, 7 days apart. Test- retest reliability of the YBT was excellent with ICC > 0.75 and a small standard error of measurement (SEM) ranging from 1.77 to 5.81%. The minimal detectable change (MDC) values were identified as 4.90 to 16.10% representing the minimum amount of change to detect repeatability. In 2017, Kim Hebert-Losier investigated the effect of hand position and lower limb measurement method on lower quarter YBT scores. She recruited 46 volunteers for this study where they completed the YBT with their hands on their hips and hands free to move. Reach distances were greater when the hands moved freely for normalized posteromedial (t91 = -6.404, P < .001; ES = 0.42, 90% CL = 60.11), posterolateral (t91 = -6.052, P< .001; ES = 0.58, 90% CL=60.16), and composite (t91= - 7.296, P< .001; ES=0.47, 90% CL=60.11) scores. The lower limb length measurement methods had trivial effects on YBT outcomes.

Detecting life-long deficits from a LAS is very difficult to capture in research on human subjects. Current research uses mouse models to replicate life-long responses to injuries and illnesses. Wikstrom et al.108 used a mouse model of mild and severe ankle sprains to quantify balance and locomotor adaptations across the lifespan. Age-related declines in balance but not stride length were exacerbated by an ankle sprain (P, .001). Balance and stride lengths changed with age (P < .001). Foot slips were worse in the severe (4.32 ± 0.98) and mild (3.53 ± 0.98) groups than in the sham group (2.16 ± 0.99; P < .001). Lifelong sensorimotor dysfunction was noted after transecting the lateral ligaments of a mouse hind foot. A decline beginning at 42 weeks post injury may coincide with the development of posttraumatic osteoarthritis.

Chronic Ankle Instability Those with a history of previous ankle sprains are twice as likely to suffer a subsequent sprain.79 Hertel, in 2002, proposed the model of chronic ankle instability (CAI) as those that suffer a subsequent sprain will be a part of a continuum of mechanical and functional instability. These components can exist separately or in conjunction.30 In 2011, Hiller et al.109 incorporated the group of those with recurrent sprains separately. They proposed that there are three groups: mechanical instability, perceived instability, and recurrent sprains. Each of these groups overlap each other where there can also be in combination of the three groups. Those with CAI perform poorly on balance tasks, specifically those with perceived instability (43%) and recurrent sprains (31%).109 Symptoms that associate with CAI are chronic pain and swelling, recurrent injury, and degenerative joint changes.110 CAI, or the presence of

functional or mechanical instability, has been shown to be independent to the severity of the original injury.111 In a cross-sectional study by Attenborough et al.112, 96 female netball players were examined to investigate recurrent sprains, perceived ankle instability and mechanical ankle instability. Forty-seven percent had recurrently sprained an ankle, of these, 64% had a moderate-severe degree of perceived ankle instability. Club players had more cases of that level of perceived instability (p = 0.01) and larger inversion- eversion angles (p = 0.001) compared to district players. In a separate article by the same authors, they sought to identify risk factors of ankle sprains in 94 netball players. Vertical jump height, perceived ankle instability, sprain history, arthrometry inversion-eversion angles, star excursion balance test, number of foot lifts and demi- pointe balance test were taken preseason. Eleven sprains were noted for eleven players with an incidence rate of 1.74/1000 hours of netball exposure. The authors noted that the posteromedial reach in the star excursion balance test of less than or equal to 77% of leg length increased the odds of sustaining an ankle sprain (OR = 4.04, 95% CI = 1.00-16.35).113 Multiple subjective questionnaires have been created to assess and include those with decreased ankle function and ankle instability, specifically the Cumberland Ankle Instability Tool (CAIT)114, the Identification of Functional Ankle Instability (IdFAI)115,116, and the Foot and Ankle Ability Measure (FAAM).117 The International Ankle Consortium recommends that all three subjective questionnaires are used to classify someone with CAI or diminished ankle function. Specific cut off points have been identified for each questionnaire to include them in CAI (CAIT < 25, IdFAI > 11, FAAM ADL < 90% and Sport < 80%). Including the questionnaires, inclusionary

criteria involve: a history of at least one significant ankle sprain at least 12 months prior to the study enrollment with inflammatory symptoms and lost at least one day of desired activity. They also must have a history of the previously injured ankle joint “giving way” and/or recurrent sprain and/or “feeling of instability.” The definition of an ankle sprain is “an acute traumatic injury to the lateral ligament complex to the ankle joint because of excessive inversion of the rear foot or a combined plantar flexion and adduction of the foot. This usually results in some initial deficits of function and disability.” The definition of “giving way” is “the regular occurrence of uncontrolled and unpredictable episodes of excessive inversion of the rear foot (usually experienced during initial contact during walking or running), which do not result in an acute lateral ankle sprain.” The definition of “recurrent sprain” as two or more sprains to the same ankle.30,117,118Previous research has also identified that those with perceived instability, have less health-related quality of life and more functional limitations compared to healthy, uninjured participants.119 Besides the potential for degenerative joint changes, those that sustain an ankle sprain may see long-term effects to their overall health if not treated appropriately.54 Recently, Hubbard-Turner et al.120 published an article on self-reported physical activity one year after an acute ankle sprain. Twenty subjects with an acute lateral ankle sprain (LAS) and 20 healthy subjects were given activity questionnaires to determine their self-reported physical activity one week before they injury compared to one year following the injury. Subjects in the LAS group scored significantly less at the one year mark compared to one week prior (p = 0.001) and less (p = 0.02) than the healthy group at one year. It has been thought by Miklovic et al.121, that an acute lateral ankle sprain (LAS) leads to CAI by a pathway of dysfunction. This pathway is led by impairments

that have been previously associated with CAI: decreased ROM, strength, postural control, and altered movement patterns during functional activities. An impairment- based rehabilitation model has been created by Donovan and colleagues74,122 and has shown to be an effective rehabilitation strategy in those with CAI. The impairment- based model, in summary, involves assessing each potential impairment for the patient and determining which note deficits, then addressing the impairment through rehabilitation.122 The purpose of their review was to compare impairments and treatment techniques in individuals with an acute LAS, sub-acute LAS, and CAI. The bottom line from this review was that similar impairments (mentioned previously) are observed in patients with acute LAS, sub-acute LAS, and CAI. Since similar impairments are seen in all groups, an impairment-based model may be effective for treating patients with an acute LAS.121 The Cumberland Ankle Instability Tool (CAIT) is a subjective questionnaire and has been used by researchers and clinicians to detect if a patient has subjective ankle instability.123–125 Wright et al.126 sought to establish the minimal detectable change (MDC) and minimal clinically important difference (MCID) for the CAIT in a population with CAI. With a convenient sample of 50 individuals with CAI including a history of an ankle sprain, recurrent episodes of giving way, and a CAIT score of £ 25, the authors found that the CAIT has an MDC and MCID of ³ 3 points. In assessing CAI over time, a minimum threshold should be used to determine if there is a clinically meaningful improvement.

Chapter 2

TALOFIBULAR INTERVAL FOLLOWING AN ACUTE LATERAL ANKLE SPRAIN

(Targeted for submission to Journal of Athletic Training)

Introduction Ankle sprains account for a large number of acute sport-related injuries presenting to the emergency department with a cost of over $1,000 per lateral ankle sprain.1 The ankle joint is the most common injured body site in an athletic population.7,8 Of all ankle injuries, sprains occur most often in the lateral ankle ligament complex to those in a collegiate setting.3–5,8,9 The sports with the highest prevalence of ankle sprains have been reported as men’s and women’s basketball, as well as women’s track, women’s soccer, and women’s field hockey.5,7,8 In a recent systematic review of all prospective epidemiology studies of ankle sprains, females have a higher incidence of ankle sprains than males (13.6 vs 6.96 per 1,000 exposures).9 The amount of time to return to full activity has been previously reported with 44% returning less than 24 hours from the injury and only 3.6% requiring more than 21 days before returning to play.5 However, return-to-play time is not affected by having previous history of ankle sprains.127 In a general clinic-based population, approximately 72% of patients following an ankle sprain reported residual symptoms six to 18 months later.10 Of those that reported residual symptoms, 40% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Factors that were associated with moderate to severe symptoms were reinjury of the ankle, activity restriction longer than one week, and limited weight bearing longer than 28 days.10 After an initial evaluation of the injury occurs, the

clinician will grade the injury (I, II, III) depending upon the severity of the injury and the symptoms presented. Grading, typically, will occur following manual stress tests, such as, the anterior drawer test and talar tilt test. Manual stress tests have been shown to be less reliable in determining stability of the talocrural joint, thus making the clinical decision of injury severity less accurate.40 This can be problematic, since understanding the severity of an ankle sprain plays a significant role in the clinician’s reasoning for specific rehabilitation protocols and time to return-to-play. Previous research has shown that approximately 30% of patients suffering an initial ankle sprain will develop chronic ankle instability.11 Chronic ankle instability (CAI) is defined by those that have suffered recurrent ankle sprains, may have prolonged symptoms, and may exhibit mechanical and/or functional instability.30 Laxity, or the amount of mechanical instability within the joint, has been previously identified as an indicator of subsequent injury to the ankle ligaments. Anterior drawer and inversion talar tilt methods have been used detected with multiple methods: stress radiography, stress ultrasonography, stress MRI, and instrumented arthrometry. Croy et al.46 demonstrated a method for determining ankle laxity with stress ultrasonography and a Telos stress device. Talofibular interval (TI) is measured as the distance between the talus and the fibula using the measuring tool on the ultrasound unit. After an acute ankle sprain, TI is greater after the injury compared to the uninjured ankle.43 Functional deficits have been seen in those with CAI, specifically including postural control or dynamic balance.95,128–131 While several purported reasons exist for these deficits, of particular interest is the difference in dorsiflexion range-of-motion between the injured and uninjured ankles. As the amount of asymmetry between the sides increases in those with CAI, the risk for injury to the

ankle increases, thus limiting their functional performance and dynamic balance tasks.87,92 Therefore, the purpose of the study was to compare mechanical laxity of the talocrural joint in a college-aged population over time after an acute ankle sprain. H2.1 We hypothesized that there would be a significant increase in the talofibular interval (TI) and stress in anterior drawer (AD) and inversion (INV) between injured (AAS) following a grade II and III ankle sprain and uninjured subjects (CON). H2.2 We hypothesized that the ankle laxity/stress from time of injury in INV would be greater in grade II and grade III ankle sprains compared to the 2-4-week time point. H2.3 Those with a greater difference in dorsiflexion range-of-motion (DFROM) (> 3 degrees) between ankles would have a similarly significant difference in TI in AD compared to CON.

Experimental Design This study utilized a post-test only design. The independent variables were time (1, 2, 3), injury severity (I, II, III), and group [acute ankle sprain (AAS) and control (CON)]. The dependent variables were INV TI (mm), INV stress (mm), AD TI (mm), AD Stress (mm) DFROM (degrees) and weight-bearing lunge test (WBLT, degrees and centimeters, cm) (Figure 2.1). Covariates were sex, height, and mass. Testing took place at three time points following an AAS: (1) 24-72 hours, (2) 2-4 weeks, and (3) 6-months. The CON group was tested on one day only, around the time of the 6-month time point in the AAS group. (Figure 2.1)

Figure 2.1: Experimental design for Chapter 2.

Participants

One hundred and eight volunteers (58 females, 50 males) were recruited for this study. All participants were university student-athletes, recreational or competitive, (Table 2.1), participating in physical activity for at least 30 minutes three times a week. Subjects were further divided into the AAS and CON groups with 55 subjects in the AAS group and 53 subjects in the CON group. (Figure 2.1) For the AAS group, all data were collected on unilateral acute ankle sprains, using the IAC definition of “ankle sprain,” within the first 24-72 hours of injury. 132 Of the AAS group, the participants were categorized depending on injury classification (Grade I, II, III). The involved limb for the AAS group, as well as approximate height and weight, were matched in the CON group. According to the IAC guidelines for CON subjects, the CON group had no history of previous ankle sprains, bilaterally, with a CAIT and IdFAI score of 30 and 0, respectively.132 Participants were excluded from the study if they had CAI bilaterally (CAIT < 24 or IdFAI > 11), were currently

seeking treatment for a separate lower extremity injury not including an ankle sprain, or have undergone any lower extremity surgery within the last year.

AAS (n = 55) CON (n = 53) N = 108 27 F/ 28 M 31 F/ 22 M 58 F/ 50 M

Age, yrs. 20.4 ± 1.9 Age, yrs. 20.3 ± 1.7 Age, yrs. 20.3 ± 1.8

Height, cm 175.9 ± 12 Height, cm 169.3 ± 10.1 Height, cm 172.7± 11.5

Mass, kg 77.4 ± 15.1 Mass, kg 68.8 ± 13.3 Mass, kg 73.3 ± 14.9 Table 2.1: Participants Demographics for AAS and CON. Mean ± SD Acute Ankle Sprain (AAS), Control (CON), years (yrs), centimeters (cm), kilograms (kg), females (F), males (M).

Instrumentation Mechanical laxity of the talocrural joint was measured using the LigMaster (LigMaster Inc., Charlottesville, VA, USA) to stress the ankle in INV and AD positions, while taking an ultrasound image (MSUS) using a GE logiq e (General Electric Company, Waukesha, WI, USA) at a 12 MHz frequency and 2.5 cm depth. The transducer head was positioned in the sinus tarsi, obliquely from the distal fibula from the origin to insertion of the ATFL.22 Ultrasonic gel (Aquasonic 100, Parker Laboratories, Inc. Fairfield, NJ) was used as a conductive medium for the sound waves to travel from the probe through the skin. Interrater reliability of the LigMaster joint arthrometer has been previously reported for the talar inversion and anterior drawer tests as 0.76 and 0.81, respectively.41 Intrarater reliability of the LigMaster for talar inversion and anterior drawer test were 0.74 and 0.65, respectively.41 For the WBLT and DF ROM, an inclinometer/protractor and tape measure were used.

Procedures

Demographic and Anthropometric Data

Participants completed an inclusion questionnaire (Appendix B) containing general information such as age, gender, height, weight, and previous lower extremity injury history. They also completed three separate surveys related to foot and ankle function and instability to determine if any of the subjects fall into CAI status, which would exclude them from this study. The three surveys included were the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports Subscales (Appendix C), Cumberland Ankle Instability Tool (CAIT) (Appendix D), and Identification of Functional Ankle Instability (IdFAI) (Appendix E).117

Injury Classification To determine injury severity/grade (I, II, III), ankle girth (edema) using a tape measure in a figure-of-eight method (Figure 2.2), DF ROM using a goniometer (Figure 2.3), and laxity measured by stress ultrasound was performed. Table 2.2 represents the methods described by Malliaropoulos et al.27 to classify ankle sprain grade. Since the classification of a grade I ankle sprains will include a negative anterior drawer test and talar tilt test, severity was analyzed separately.

Grade Decreased ROM Edema Stress I Up to 5 degrees Up to 0.5 cm normal II 5 to 10 degrees 0.5 cm to 2 cm normal IIIA More than 10 degrees More than 2 cm normal IIIB More than 10 degrees More than 2 cm Laxity greater than 3 mm

Table 2.2: Injury Classification for AAS (Grade I-III)

Figure 2.2: Figure-of-eight method.

Figure 2.3: Dorsiflexion range of motion (degrees). Neutral start position (0 degrees).

Weight-Bearing Lunge Test (WBLT)

The WBLT was administered using the methodology described by Bennell et al.85 The ROM in degrees and the distance away from the wall in centimeters was collected. Three trials were done with the maximal range-of-motion used for analysis. If the participant easily reaches the wall with their toes at 10 cm, the trial was redone at a further distance 1 cm at a time until the maximal distance and range is achieved. The same was done if the participant is unable to touch the wall without their heel rising at 10 cm. The foot moved closer to the wall 1 cm at time until their maximal

distance and range was achieved. The inclinometer was placed on the participant’s anterior distal tibia. (Figure 2.4)

Figure 2.4: Position for Weight-Bearing Lunge Test.

Dorsiflexion Range-of-Motion (DF ROM)

The participant was asked to sit up on the plinth supporting him/herself on outstretched arms with their legs straight and ankles hanging off the table. With a goniometer using the methods from Malliaropoulos et al.,27 the axis was placed at the distal edge of the lateral malleolus, the stationary arm was in line with the mid line of the fibula and the movement arm is parallel to the 5th metatarsal. (Figure 2.3) The participant was asked to hold a neutral position, which is 0 degrees on the goniometer. They were asked to pull their foot with their toes back toward them as far as they could. Three measurements were taken, and the greatest measure was used for comparison. The uninvolved ankle was measured first, followed by the involved ankle.

Inversion Talofibular Interval (INV TI) The participant was placed into the LigMaster device using the guidelines for inversion.133 The counter bearing was placed near the lateral knee without placing pressure on the knee joint line. A cushion was placed underneath the patient’s distal hamstring for added comfort. The pressure actuator was placed with the edges of the rubber padding on the pressure place at the level of the most medial point on the medial malleolus (Figure 2.5-A). A force of 12-15 dN was then applied to the joint. MSUS Images were taken over the ATFL with three images at maximal stress position (Figure 2.5-B), or to the participants pain tolerance level.40,41 A measure was taken, using the ultrasound measure function, as the distance between the peaks of the lateral malleolus and talus, or TI, which will constitute the anatomic origin and insertion of the ATFL (Figure 2.6-A).43,45 The opposite, uninjured ankle was used to compare with the injured ankle during this timeline. An average of the three images was used for analysis and a difference was taken between the injured and uninjured ankles.43 INV stress was defined as the distance between the peak of the talus and fibula at the maximal stress position. INV TI was defined as the difference between stress and static measures.

Figure 2.5: Inversion Talofibular Interval (a) Static position (b) Stressed position. 61

B A

FIBULA

TALUS

Figure 2.6: Musculoskeletal Ultrasound . (A) Talofibular Interval (B) Anterior Talofibular Ligament thickness.

Anterior Drawer Talofibular Interval (AD TI)

The participant was placed into the LigMaster device using the methods from Croy et al.43 The participant was asked to lay side lying on the opposite side as the test ankle. The pressure actuator was placed with the edges of the rubber padding on the pressure place at the level of the 5.0 cm proximal to the medial malleolus (Figure 2.7). A force of 12-15 dN was applied to the joint. MSUS Images were taken over ATFL with three images at maximal stress position (12-15 dN).40,41 A measure was taken, using the ultrasound measure function, as the distance between the peaks of the lateral malleolus and talus, or TI, which will constitute the anatomic origin and insertion of the ATFL (Figure 2.6- A).43,45 The opposite, uninjured ankle was used to compare with the injured ankle during this timeline. An average of the three images was used for analysis and a difference was taken of the injured and uninjured ankles.46 AD stress was defined as the distance between the peak of the talus and fibula at the maximal stress position. AD TI was defined as the difference between stress and static measures.

Figure 2.7: Anterior Drawer Talofibular Interval, Static position.

Statistical Analysis To answer the proposed aim, the following statistical analyses were used: 1) repeated-measures analysis of variance (ANOVA) to analyze AD and INV TI and stress, DF ROM, and WBLT for the AAS group over the three time points (24-72 hours, 2-4 weeks, and 6 months); 2) independent sample t-tests to compare the variables across the two groups (AAS and CON) at the 6-month time point; 3) one- way ANOVA to compare the variables across the three grades of severity (Grade I,

Grade II, Grade III) in AAS during the three time points; 4) a linear mixed model to analyze the dependent variables between injured and uninjured ankles across time. Cohen’s d effect sizes were reported to determine the standardized difference in the means of significant findings. A small effect size was represented by 0.2, medium by 0.5, and large as 0.8. All data were analyzed using the Statistical Package for Social

Sciences Version 25 (SPSS, Chicago, IL). An a priori alpha level of .05 was used to denote statistical significance.

Results The results of the study are presented by dependent variable and by analysis. Each variable (injury classification and function, WBLT, DFROM, INV TI/stress, AD TI/stress) was assessed in AAS group over time, by group at 6-months, by ankle sprain severity over time, and between ankles in the AAS group.

Injury Classification and Function

Those who sustained an acute lateral ankle sprain, 21 of 55 (38%) were Grade I, 27 of 55 (49%) were Grade II and 7 of 55 (13%) were Grade III. On the injured ankle, these participants had an average of 2.16 ± 2 previous LAS. Forty-three participants of the AAS (78%) were collegiate student-athletes at the Division I or II level. The remaining 12 of the AAS group were recreationally active students.

AAS Over Time Differences were found over time in the AAS group in girth between time 1 and 3 (p < .001, 95% CI: 1.872 – 3.258), between time 1 and 2 (p < .001, 95% CI: .556 – 1.579), and between time 2 and 3 (p < .001, 95% CI: .994 – 2.001). (Table 2.3,

Figure A.1) Significant differences were noted over time in the AAS group in IdFAI between time 1 and 2 (17.1 ± 1.8 vs 21.4 ± 1.3, p = .023, 95% CI: .512 – 8.155) and between time 2 and 3 (21.4 ± 1.3 vs 16.4 ± 1.2, p = .005, 95% CI: 1.352 – 8.731). No significant differences were seen between time 1 and 3 (p = 1.00). Differences were found over time in the AAS group in CAIT between time 2 and 3 (19.2 ± 1.3 vs 23.3 ± 1.3, p = .035, 95% CI: .240 – 8.021). No significant differences were noted between

time 1 and 2 (p = 1.0) and between time 1 and 3 (p = .342). Differences were found over time in the AAS group in FAAM-ADL between time 1 and 2 (48.1 ± 6.4 vs 70.4 ± 3.3, p = .019, 95% CI: 3.201 – 41.380) and between time 1 and 3 (48.1 ± 6.4 vs 81.0 ± .66, p < .001, 95% CI: 16.168 – 49.587). No significant differences were noted between time 2 and 3 (p = .063). Differences were found over time in the AAS group in FAAM-Sport between time 1 and 2 (9.8 ± 2.1 vs 20.3 ± 2.3, p = .001, 95% CI: 4.508 – 16.475) and between time 1 and 3 (9.8 ± 2.1 vs 26.8 ± 1.0, p < .001, 95% CI: 11.506 – 22.566) and between time 2 and 3 (20.3 ± 2.3 vs 26.8 ± 1.0, p = .036, 95% CI: .355 – 12.734).

Group at 6-months In comparing the AAS and CON groups at 6-months, there was no statistical differences in girth in cm (F= 3.72, p= .288). (Table 2.4) There were significant differences between groups (AAS and CON) in IdFAI (16.6 ± 6.4 vs 2.47 ± 2.6, p < .001, F = 27.440), CAIT (23.3 ± 6.5 vs 28.8 ± 1.9, p < .001, F = 18.362), FAAM-ADL (79.3 ± 10.8 vs 83.5 ± 1.4, p = .008, F = 10.917) and FAAM-Sport (27.6 ± 4.7 vs 31.8 ± .66, p = .027, F = 76.586).

AAS by Severity

Using a one-way ANOVA to examine differences between severity of ankle sprain (Grade I-III), FAAM-Sport at time 1 was significantly different between Grade I and Grade III (p = .030). No significant differences were noted between grades for IdFAI (p = .360, F = 1.045), CAIT (p = .486, F = .734), FAAM-ADL ( p = .101, F = 2.441), and girth (p = .788, F = .239). At time 2, FAAM-Sport was significantly different between Grade I and Grade III (p = .026) and Grade I and Grade II (p =

.034). During this time, CAIT was significantly different between Grade I and Grade III (p = .006) and between Grade II and III (p = .043). IdFAI and FAAM-ADL were not significantly different between grades (p = .539 and p = .080, respectively). At time 3, the CAIT was significantly different between the grades (p = .034), however, between Grade I and Grade II (p = .070) and between Grade I and III (p = .063) were approaching significance. During this time, FAAM-Sport was significantly different between Grade I and Grade III (p = .041). There were no differences at time 3 in IdFAI, FAAM-ADL, and girth.

AAS Over Time Between Ankles

A mixed model analysis determined the differences between the involved (AAS) ankle and the uninvolved ankle at each time point. Significant differences between the ankles were noted for each time point in IdFAI (p < .001), CAIT (p < .001), FAAM-ADL (p < .001), FAAM-Sport (p < .001), and girth (p < .001).

WBLT

The weight-bearing lunge test (WBLT) was examined in the study using two methods described previously as the angle of the tibia during DF in degrees and the distance between the toe and the wall in cm, each measured during the lunge test.

AAS Over Time Over time, significant differences were seen between time 2 and 3 in WBLT in cm (p < .001, t = -5.805, df = 39). Significant differences were noted between time 2 and 3 in WBLT in deg (p < .001, t = -4.252, df = 39). (Table 2.3)

Group at 6-months In comparing the AAS (all grades) and CON groups at 6-months, there were no statistical differences in WBLT in cm (p= .199, F = .241) or degrees (p= .173, F = .169). (Table 2.4)

AAS by Severity

At time 1, WBLT was not collected. (Table 2.5) At time 2, WBLT in degrees in approaching significant differences by severity (p = .053, F = 3.134). WBLT in cm was not significantly different at time 2 (p = .080). (Table 2.6) At time 3, by severity, approaching significant differences in WBLT in cm were noted (p = .061, F = 2.982). No significant findings were seen in WBLT in degrees (p = .174). (Table 2.7)

AAS Over Time Between Ankles Significant differences were noted between involved and uninvolved ankles at time 2 in WBLT in cm (p < .001) and in degrees (p < .001). Significant differences were also noted between involved and uninvolved ankles at time 3 in WBLT in cm (p < .001) and in degrees (p < .001).

DFROM

AAS Over Time

Over time in the AAS group, significant differences were noted in DFROM between time 1 and 2 (5.7 ± .47 vs 8.3 ± .59 degrees, p < .001, 95% CI: 1.393 – 3.724), and between time 2 and 3 (8.3 ± .59 vs 9.9 ± .55 degrees, p = .047, 95% CI: .017 – 3.239), and between time 1 and 3 (5.7 ± .47 vs 9.9 ± .55 degrees, p < .001, 95% CI: 2.765 – 5.607). (Table 2.3)

Group at 6-months In comparing the AAS and CON groups at 6-months, there was no statistical difference in DFROM in degrees using a goniometer (p= .358, F= .076). (Table 2.4)

AAS by Severity

In the AAS group between severity (Grade I-III), DFROM was significantly different between Grade I and Grade III (p = .004, F = .394) at time 1. (Table 2.5, Figure A.2) No significant difference was seen between grades at time 2 (p = .677). (Table 2.6) No significant difference was noted between grades at time 3 (p = .980). (Table 2.7)

AAS Over Time Between Ankles DFROM measured in degrees was significantly different between the involved and the uninvolved ankles (p < .001) at each time point.

INV TI/ Stress

AAS Over Time

Over time in the AAS group, significant differences were noted in INV stress (p = .047); however, the differences noted between time 1 and 2 (p = .065) and between time 2 and 3 (p = .072) were approaching significance. Significant differences were noted in INV TI between time 1 and 2 (p = .001, 95% CI: .801 – 3.651). However, no differences were seen between time 1 and 3 (p = .165) and time 2 and 3 (p = .475). (Table 2.3, Figure A.3)

Group at 6-months In comparing the AAS and CON groups at 6-months, there was a statistical difference in INV TI (p= .002). There was statistical increase in INV TI (F= 2.314, p= .004) in the AAS group (all grades) compared to CON at 6-months. There was statistical increase in INV stress (p< .001) in the AAS group compared to CON at 6- months. (Table 2.4, Figure A.4)

AAS by Severity

In the AAS group between severity (Grade I-III), INV stress was significantly different between Grade I and Grade III (p = .023) and Grade I and Grade II (p = .035) at time 1. (Figure A.5) However, no differences were noted between Grade II and III (p = .651) (Table 2.5) There were no significant differences in INV stress or TI by severity at time 2. (Table 2.6) There were no significant differences in INV stress or TI by severity at time 3. (Table 2.7)

AAS Over Time Between Ankles Significant differences were noted between the involved and uninvolved ankles at time 1 in INV TI (p < .001), however, no differences were noted between ankles at time 2 and time 3 (p = .603 and p = .157, respectively).

AD TI/ Stress

AAS Over Time

Over time in the AAS group, no significant differences were detected in the AAS group over time in AD TI (p = .280, F = 1.723) and AD stress (p = .228, F= 1.506). (Table 2.3, Figure A.2)

Group at 6-months There was a statistical increase in AD stress (p= .001) in the AAS group compared to CON at 6-months. In comparing the AAS and CON groups at 6-months, there was no statistical difference in AD TI (p= .219). (Table 2.4, Figure A.4)

AAS by Severity

In the AAS group between severity (Grade I-III), AD TI was significantly different between Grade I and Grade II (p = .009) at time 1. (Table 2.5, Figure A.5) There were no significant differences in AD stress or TI between severity at time 2 and 3. (Table 2.6 & 2.7)

AAS Over Time Between Ankles Between ankles, there were no significant differences in AD TI at time 1 (p = .219) and time 2 (p = .095), however, there were differences at time 3 (p = .017).

1 2 3 p- 24-72 hrs. 2-4 weeks 6-months value Girth, cm 51.7 ± 3.8* 50.7 ± 4.2* 49.2 ± 3.9* < .001 DFROM, deg 5.8 ± 3.2* 8.3 ± 3.7* 9.9 ± 3.7* < .001 WBLT, cm X 6.6 ± 3.8* 9.0 ± 3.5* < .001 WBLT, deg X 37.2 ± 10.5* 42.7 ± 8.1* < .001 AD TI, mm 1.7 ± 1.7 1.5 ± 2.3 1.0 ± 2.1 .185 INV TI, mm 1.9 ± 2.9* -.21 ± 2.5* .57 ± 2.3 .001 AD Stress, mm 22.4 ± 3.8 21.9 ± 2.9 22.7 ± 3.6 .228 INV Stress, mm 22.1 ± 3.1 21.1 ± 3.6 22.3 ± 3.1 .047

Table 2.3: Injury Classification and Ankle Laxity Over Time. Mean ± SD (DFROM= dorsiflexion range-of-motion, WBLT= weight-bearing lunge test, AD= anterior drawer, TI= talofibular interval, INV= inversion, mm = millimeters, cm = centimeters, deg = degrees)

Cohen’s AAS (n=46) CON (n=54) p-value d Girth, cm 49.3 ± 3.9 48.5 ± 3.0 .29 DFROM, deg 9.9 ± 3.6 10.6 ± 3.9 .36 WBLT, cm 8.8 ± 3.6 9.8 ± 3.6 .19 WBLT, deg 42.4 ± 8.3 44.9 ± 10.1 .17 AD TI, mm 1.01 ± 2.1 .53 ± 1.7 .22 INV TI, mm .72 ± 2.5 -.88 ± 2.4 .002 .65 AD Stress, mm 22.7 ± 3.6 20.6 ± 2.8 .001 .65 INV Stress, mm 22.3 ± 3.1 19.4 ± 2.9 <.001 .96

Table 2.4: Injury Classification and Ankle Laxity by Group All Grades at 6- months. Mean ± SD (DFROM= dorsiflexion range-of-motion, WBLT= weight-bearing lunge test, AD= anterior drawer, TI= talofibular interval, INV= inversion, mm = millimeters, cm = centimeters, deg = degrees, AAS = acute ankle sprain, CON = control)

p- I (n=21) II (n=24) III (n=5) value Girth, cm 52.0 ± 3.7 52.6 ± 4.4 51.6 ± 1.5 .79 DFROM, deg 7.2 ± 3.1* 5.5 ± 2.9 2.2 ± 1.9* .003 AD TI, mm .88 ± 1.7* 2.4 ± 1.6* 1.4 ± 1.3 .012 INV TI, mm 1.1 ± 2.5 2.4 ± 3.3 3.5 ± 2.0 .15 AD Stress, mm 21.6 ± 3.3 23.0 ± 4.2 22.6 ± 3.8 .48 INV Stress, mm 20.7 ± 2.2* 22.9 ± 3.2* 24.6 ± 3.2* .007

Table 2.5: Injury Classification and Ankle Laxity in AAS by Grade at 24-72 hours. Mean ± SD

(DFROM= dorsiflexion range-of-motion, WBLT= weight-bearing lunge test, AD= anterior drawer, TI= talofibular interval, INV= inversion, mm = millimeters, cm = centimeters, deg = degrees, AAS = acute ankle sprain)

p- I (n=22) II (n=27) III (n=6) value Girth, cm 51.7 ± 4.2 51.8 ± 4.3 47.9 ± 2.5 .11 DFROM, deg 8.3 ± 3.8 8.2 ± 3.9 6.8 ± 1.6 .68 WBLT, cm 7.8 ± 3.2 6.2 ± 4.0 3.6 ± 2.9 .08 WBLT, deg 40.5 ± 8.2 35.6 ± 8.7 28.2 ± 20.2 .053 AD TI, mm 1.2 ± 2.4 1.7 ± 2.6 2.1 ± 1.4 .66 INV TI, mm -.75 ± 2.5 .09 ± 2.3 .38 ± 2.6 .41 AD Stress, mm 21.4 ± 2.8 22.4 ± 3.2 21.7 ± 2.8 .49 INV Stress, mm 19.6 ± 2.6 21.8 ± 4.2 22.4 ± 2.9 .056

Table 2.6: Injury Classification and Ankle Laxity in AAS by Grade at 2-4 weeks. Mean ± SD (DFROM= dorsiflexion range-of-motion, WBLT= weight-bearing lunge test, AD= anterior drawer, TI= talofibular interval, INV= inversion, mm = millimeters, cm = centimeters, deg = degrees, AAS = acute ankle sprain)

p- I (n=16) II (n=24) III (n=6) value Girth, cm 49.3 ± 3.9 49.8 ± 4.0 47.0 ± 2.4 .29 DFROM, deg 9.8 ± 3.7 9.9 ± 3.7 10.2 ± 3.7 .98 WBLT, cm 10.2 ± 2.9 7.6 ± 3.8 9.7 ± 3.4 .06 WBLT, deg 44.5 ± 8.2 40.2 ± 8.1 45.5 ± 8.3 .17 AD TI, mm .42 ± 2.4 1.27 ± 2.16 1.5 ± .66 .40 INV TI, mm .93 ± 2.5 .58 ± 2.7 .71 ± 2.5 .90 AD Stress, mm 22.0 ± 4.0 23.2 ± 3.5 22.5 ± 2.2 .58 INV Stress, mm 21.8 ± 2.2 22.7 ± 3.7 21.9 ± 2.3 .66

Table 2.7: Injury Classification and Ankle Laxity in AAS by Grade at 6-months. Mean ± SD (DFROM= dorsiflexion range -of-motion, WBLT= weight-bearing lunge test, AD= anterior drawer, TI= talofibular interval, INV= inversion, mm = millimeters, cm = centimeters, deg = degrees, AAS = acute ankle sprain)

Discussion The long-term effects of an acute lateral ankle sprain on ankle joint laxity and ankle joint function have not been previously identified in this specific population compared to a healthy uninjured cohort. The purpose of the current study was to compare mechanical laxity of the talocrural joint in a college-aged population over time after an acute ankle sprain. The primary findings were that, at 6-months following an ankle sprain compared to a healthy, control group, significant differences in laxity exist. A significant increase in AD stress, INV stress, and INV TI was noted between the groups at that time. Between severity, at 24-72 hours, a significant increase was seen in AD TI and INV stress between Grade I and II, as well as, Grade I and III in INV stress. At 2-4 weeks, a significant increase in INV stress was still noted between Grade I and II.

Injury Classification

In those who sustained an acute lateral ankle sprain, 38% (21 of 55) were Grade I, 49% (27 of 55) were Grade II and 13% (7 of 55) were Grade III. Our distribution pattern was similar to the previous research by Malliaropoulos et al.27 identified the distribution of ankle sprain severity in track and field athletes as 44% (92 of 208) Grade I, 30% (63 of 208) Grade II, and 26% (53 of 208) Grade III.27 Our results were not surprising as we used the same criteria put forth by Malliaropoulos et al.27 in classifying the severity of the ankle sprain. It is important, when assessing the ankle for a potential lateral ankle sprain, that severity is considered by using outcome measures, such as ROM, swelling, ecchymosis, stress tests, tenderness to palpate (TTP), pain, and functional performance.

As we noted, girth significantly decreased over time in the AAS group, which was to be expected as tissue healing occurs over time. IdFAI scores decreased between 2-4 weeks and 6-months. For CAIT, scores stayed consistent in the injured ankle between time 24-72 hours and 2-4 weeks, however, increased at 6-months. In FAAM- ADL and FAAM-Sport, a significant increase in score occurred in the AAS group between 24-72 hours and 2-4 weeks, with a smaller increase between 2-4 weeks and 6- months. Croy et al.43 found a significant increase in both FAAM-ADL and FAAM- Sport from baseline to week 3 (21.9 ± 16.2, p < .0001 and 23.8 ± 16.9, p < .0001) and from week 3 to week 6 (2.5 ± 4.4, p = .009 and 10.5 ± 13.2 p = .001).

WBLT There was decrease in WBLT in AAS compared to CON at 6-months. In a Grade II or III ankle sprain, the structure of the ATFL has been disrupted and during the remodeling phase, scar tissue is built up around the repairing ligament.23,25 This scar tissue is less mobile than an intact ligament. Previous work concluded that this may cause a shift in the position of talus and that it may sit more anteriorly, causing a decrease in DF ROM of the ankle.71 We postulate that this to be the reason a decrease in WBLT in those with a Grade II and III ankle sprain was noted. The WBLT measures DF ROM in a weight-bearing position and has previously been accepted as a reliable method of measuring DF ROM over a goniometric measurement in a non- weight bearing position.90,93 We contend that the WBLT is important to utilize and monitor in those who sustain a Grade II or III ankle sprain to make sure differences do not exist over time.

DFROM Over time in the AAS group, DFROM significantly increased between 24-72 hours and 2-4 weeks, however, a smaller increase was noted at 6-months. DFROM was significantly less in Grade III ankle sprains compared to Grade I within the first 24-72 hours. The measure of DFROM was taken in a supine position during this time due to the injured participant having pain during weight-bearing activities. Previous research is limited on the differences observed in the WBLT and DFROM results across severity of ankle sprain.134 Our classification of the injury during the first 24-72 hours was dependent on the measured DFROM and difference between the injured and uninjured ankles, thus the reason for the difference between grades. As DFROM improves over time in those with an AAS, it may be important to consider the difference between the injured and uninjured limb as well over time.

AD TI/ Stress

There was an increase in AD stress in the AAS group compared to CON at 6- months. AD TI was significantly different between Grade I and Grade II in AAS within the first 24-72 hours. Croy et al.43 observed bilateral stress ultrasound imaging at baseline (< 7 day) and on the affected ankle at 3 week and 6 week from injury in three conditions: neutral, anterior drawer, and inversion. To our knowledge, the authors were the first to discuss the talofibular interval changes from a neutral position. However, we described the talofibular interval in mm as the difference of the stressed to static position on the MSUS image. The anterior drawer stress increased TI in the involved ankle (22.65 ± 3.75 mm p = .017) compared to the uninvolved ankle (19.45 ± 2.35 mm) at baseline. Our results show that those who have sustained an

acute lateral ankle sprain (LAS) still have differences in ankle laxity compared to a healthy control group, 6-months following the ankle sprain.

INV TI/ Stress There was a significant decrease in INV stress between 2-4 weeks and 6- months, and in INV TI between 24-72 hours and 2-4 weeks in the AAS group. However, in comparing with a CON group, an increase in INV TI and INV stress was noted. In the AAS group between severity (Grade I-III), INV stress was significantly different between Grade I and Grade III and Grade I and Grade II at 24-72 hours. INV stress was significantly different between Grade I and Grade II 2-4 weeks. These differences between severity in INV stress indicate that determining severity at 24-72 hours was correctly placed by indicating the variation of laxity present. Croy et al.43 observed that inversion stress resulted in greater interval changes (23.41 ± 2.81 mm) than the uninvolved ankle (21.13 ± 2.08 mm). The authors reported a main effect for time for inversion (F 2,52 = 4.3, p= .019, 21.93 ± 3.75 mm) but not anterior drawer (F

2,52 = 3.1, p= .055, 21.18 ± 2.34 mm), which is in line with our results. Talofibular interval reduced between baseline and week 3 for inversion only (F 1,26 = 5.6, p= .026). Similarly, in the present study, TI significantly reduced from 24-72 hours to 2-4 weeks following the injury. This previous research, however, did not use a control or healthy group for comparison. They used the opposite, uninvolved ankle for comparison. The time points used also extended the time at baseline which was less than 7 days from injury and up to 6 weeks from the injury. In our study, a 6-month time point was used to determine long-term effects of ankle laxity noted via stress ultrasonography. The results from the present study show that those who have

sustained an acute LAS still have differences in ankle laxity compared to a healthy, control group, 6-months following the ankle sprain.

Conclusion At 6-months following a LAS compared to a healthy, control group, significant differences in laxity exist. A significant increase in anterior drawer and inversion/talar tilt was noted between the groups at that time. Between severity, at 24-72 hours, Grade II and III ankle sprains have greater anterior drawer and inversion stress. At 2-4 weeks, Grade II ankle sprains have increased inversion stress compared to Grade I ankle sprains. Interestingly, this difference at 2-4 weeks may indicate the long-term effects seen between the severity of ankle sprains.

Chapter 3

THICKNESS OF THE ANTERIOR TALOFIBULAR LIGAMENT FOLLOWING AN ACUTE ANKLE SPRAIN

(Targeted for submission to Journal of Athletic Training)

Introduction

Injuries to the foot and ankle account for a large percentage of injuries to an athletic population.3,8,135 Of those, lateral ankle sprains have the highest prevalence with a cost of over $1,000 per lateral ankle sprain. Lateral ankle sprains occur during an inversion and plantar flexion mechanism, which causes strain to the anterior talofibular ligament (ATFL), calcaneofibular ligament (CFL) and posterior talofibular ligament (PTFL), or the lateral ligament complex (LLC). The structure, attachment location, and composition of the ATFL is important in relation to ankle sprains since it is the weakest and most commonly sprained of the LLC. The ATFL is a crucial ligament involved in the stability of the talocrural joint. During ankle joint motion, the ATFL elongates more during plantar flexion and inversion and with excessive loading conditions, the ATFL is more vulnerable in plantar flexion (16.2 degrees) and inversion.19,20 Musculoskeletal ultrasound (MSUS) is an imaging method previously used to determine the injury to the ATFL.45,59,69,75 Characteristics can be noted on the image taken over the sinus tarsi of the ankle, where the ATFL lies. Areas of injury can be detected by the hypoechoic or hyperechoic portions over the ligament near the talar or fibular ends. As an ankle sprain occurs, the injury will most commonly occur at the

ends of the ligament. The areas that are hypoechoic, or darker, may show either inflammation or tearing of the ligament tissue and the hyperechoic, or lighter, areas may show swelling outside of the ligament.69 Those that have had multiple ankle sprains or have developed chronic ankle instability (CAI) or the presence of pain, instability, and recurrent ankle sprains, have a thicker ATFL22 and increased talocrural joint laxity.136–138 A portion of the MSUS image that we speculate may be connected to previous ankle sprains, is the development of a talar notch, or a small dip in the rounded talar surface where the ATFL inserts. As the ligament heals following an injury, it is unknown to whether this would appear in those following an AAS compared to a healthy group. Ligament thickness of the ATFL, using MSUS, has been previously reported to be increased in those with a history of previous ankle sprains, however, the number of repeated ankle sprains did not have an impact on ATFL thickness.22,139 This increase in thickness may be due to the amount of scar tissue on the ligament after a previous stretch or tear. It is unknown whether these differences would be seen over time after an acute lateral ankle sprain and also if the severity of the ankle sprain would affect the thickness as well. Therefore, the purpose of the current study was to examine the difference in thickness of the ATFL in a college-aged population over time after an acute ankle sprain (AAS). H3.1 We hypothesized that the thickness of the ATFL would be greater at 6 months compared to 24-72 hours in AAS. H3.2 We also hypothesized that the thickness of the ATFL would be greater at 6 months in the AAS compared to a healthy, control group (CON).

Experimental Design This study utilized a post-test only design. The independent variables were time (1, 2, 3), injury severity (I, II, III), and group (AAS, CON). The dependent variables were ATFL thickness (mm) (Figure 3.1), presence of pain (visual analog scale, VAS, cm; tenderness to palpate score, TTP) and a talar notch deformity on the ultrasound image. Covariates were sex, height, and mass. Testing took place at three time points following the injury for the AAS group: (1) 24-72 hours, (2) 2-4 weeks, and (3) 6-months. The CON group was tested on one day only, around the time of the 6-month time point in the AAS group.

Figure 3.1: Experimental Design for Chapter 3.

AAS group, all data were collected on unilateral acute ankle sprains, using the IAC definition of “ankle sprain,” within the first 24-72 hours of injury.132 Of the AAS group, the participants were categorized depending on injury classification (Grade I, II, III). The involved limb for the AAS group, as well as height and weight, was matched in the CON group. According to the IAC guidelines for CON subjects, the CON group had no history of previous ankle sprains, bilaterally, with a CAIT and IdFAI score of 30 and 0, respectively.132 Participants were excluded from the study if they had CAI bilaterally (CAIT < 24 or IdFAI > 11), were currently seeking treatment for a separate lower extremity injury not including an ankle sprain, or have undergone any lower extremity surgery within the last year.

Instrumentation Thickness of the ATFL was measured by musculoskeletal ultrasound (MSUS) using a GE logiq e (General Electric Company, Waukesha, WI, USA) at a 12 MHz frequency and 2.5 cm depth. The position of the transducer head was positioned in the sinus tarsi, obliquely from the distal fibula from the origin to insertion of the ATFL.22 Ultrasonic gel (Aquasonic 100, Parker Laboratories, Inc. Fairfield, NJ) was used as a conductive medium for the sound waves to travel from the probe through the skin. Reliability of this measure has been previously reported by Liu et al. (ICC= 0.91).22

Procedures

Demographic and Anthropometric Data Participants completed an inclusion questionnaire (Appendix B) containing general information such as age, gender, height, weight, and previous lower extremity injury history. They also completed three separate surveys related to foot and ankle

function and instability to determine if any of the subjects fall into CAI status, which would exclude them from this study. The three surveys included were the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports Subscales (Appendix C), Cumberland Ankle Instability Tool (CAIT) (Appendix D), and Identification of Functional Ankle Instability (IdFAI) (Appendix E).117

Injury Classification To determine injury severity/grade, ankle girth (edema) using a tape measure in a figure-of-eight method, DF ROM using a goniometer, and laxity measured by the TI was performed. Table 2.2 represents the methods described by Malliaropoulos et al.27 to classify ankle sprain grade.

Pain

At the beginning of each testing session, the participant was asked using a Visual Analog Scale (VAS) of 0 to 10 cm to report their pain at that current moment in each ankle, where 0 = no pain and 10 = unbearable pain. The next pain measure was a subjective clinical outcome of tenderness to palpate (TTP) over the sinus tarsi. A TTP scale was created from 0 to 2, where 0 would be no pain/discomfort compared to the other ankle, 1 would be a mild, dull discomfort, and 2 would be a sharp pain, compared to the other ankle. The TTP was collected while palpating both ankles at the sinus tarsi, simultaneously.

Anterior Talofibular Ligament (ATFL) Thickness The participant was asked to sit up on plinth supporting him/herself on outstretched arms behind his/her back. The examination leg was extended, and the opposite leg was flexed at the knee. The patient’s heel was placed and fixated into the

ankle holding device with the ankle in a neutral foot position. MSUS images were taken over the ATFL. (Figure 3.2) Three images were taken in the resting position without stress applied. The thickness measure (Figure 2.6- B) was taken from the midpoint of the ligament between the attachments on the lateral malleolus and talus using the built-in measuring tool on the MSUS, using previously identified methodology by Liu et al.22 An average of the three images was used for analysis. The opposite, uninjured ankle was used to compare with the injured ankle. The presence of a talar notch (Figure 3.3) would be taken from the same image as the thickness measure and would be recorded if it was present in all three images on a binary scale, 0 for no and 1 for yes.

Figure 3.2: Position of Musculoskeletal Ultrasound probe over the Anterior Talofibular Ligament.

Fibula

Talus

Figure 3.3: Musculoskeletal Ultrasound Image over the Anterior Talofibular Ligament with Talar Notch.

Statistical Analysis To answer the proposed aim, the following statistical analyses were employed: 1) repeated-measures analysis of variance (ANOVA) to analyze ATFL thickness for the AAS group over the three time points (24-72 hours, 2-4 weeks, and 6 months); 2) independent sample t-tests to compare ATFL thickness across the two groups (AAS and CON) at the 6-month time point; 3) one-way ANOVA to compare the variables across the three grades of severity (Grade I, Grade II, Grade III) in AAS during the three time points; 4) a linear mixed model to analyze the dependent variables between injured and uninjured ankles across time. Cohen’s d effect sizes were reported to determine the standardized difference in the means of significant findings. A small effect size was represented by 0.2, medium by 0.5, and large as 0.8. All data were analyzed using the Statistical Package for Social Sciences Version 25 (SPSS, Chicago, IL). An a priori alpha level of .05 was used to denote statistical significance.

Results The results of the study are presented by dependent variable and by analysis. Each variable (ATFL thickness, talar notch, and pain) was assessed in AAS group over time, by group at 6-months, by ankle sprain severity over time, and between ankles in the AAS group.

ATFL Thickness

AAS Over Time Over time, there were no significant differences in ATFL thickness (p = .399, F = .929). (Table 3.1)

Group at 6-months There was a statistical increase in ATFL thickness (p< .001, F = 12.372) in the AAS group compared to CON at 6-months (2.1 ± .49 mm vs 1.8 ± .11 mm, respectively). (Table 3.2, Figure A.6)

AAS by Severity

ATFL thickness was significantly different at time 1 between Grade I and Grade III (p = .004, 95% CI: .198 – 1.24). (Table 3.3) At time 2, ATFL thickness was significantly different between Grade I and Grade II (p = .015, 96% CI: .034 – .407). (Table 3.4) At time 3, ATFL thickness was not significantly different between Grade I-III. (Table 3.5, Figure A.7)

AAS Over Time Between Ankles There were significant differences between the involved and uninvolved ankles in ATFL thickness at time 1 (p < .001, -.29 mm), time 2 (p < .001, -.25 mm), and time 3 (p < .001, -.26 mm).

Talar Notch

Of the AAS group, 49% (27 of 55) had the characteristic of a talar notch on the MSUS image. In the CON group, 0 of 53 had the characteristic of a talar notch on the MSUS image.

Pain

AAS Over Time Differences were observed over time in the AAS group for pain using the VAS between each time period (F = 26.394, p < .001), between time 1 and 2 (p < .001, 95% CI: .756 – 2.128), time 1 and 3 (p < .001, 95% CI: 1.327 – 2.720), and time 2 and 3 (p = .001, 95% CI: .217 – .945). Differences were observed over time in the AAS group for pain using TTP between each time period (F = 29.308, p < .001), between time 1 and 2 (p < .001, 95% CI: .356 – 1.059), time 1 and 3 (p < .001, 95% CI: .659 – 1.389), and time 2 and 3 (p = .042, 95% CI: .009 – .625). (Table 3.1)

Group at 6-months

There was an increase in VAS (F= 22.966, p= .027) and TTP (F= 247.494, p< .001) in the AAS group compared to CON at 6-months. (Table 3.2)

AAS by Severity At time 1 and 2, no significant differences were noted in pain using VAS by Grade I-III (p = .544 and p = .758, respectively). At time 3 in the AAS group, there were significant differences in pain using VAS between Grade I and Grade III (p = .009, 95% CI: .17 – 1.37) and Grade II and Grade III (p = .008, 95% CI: .17 – 1.33). At time 1, 2 and 3, no significant differences were noted in pain using TTP by Grade I-III (p = .094, p = .199 and p = .514, respectively). (Table 3.3-3.5)

1 2 3 p-value 24-72 hrs. 2-4 weeks 6-months ATFL thickness, mm 2.2 ± .3 2.1 ± .2 2.1 ± .2 .40 Pain, VAS, cm 2.1 ± 1.9* .65 ± 1.4* .07 ± .67* <.001 Pain, TTP 1.5 ± .11* .81 ± .13* .49 ± .10* <.001

Table 3.1: ATFL thickness and Pain in AAS Over Time.

Mean ± SD (mm= millimeters, ATFL = anterior talofibular ligament, VAS = visual analog scale (0- 10 centimeters, cm), TTP = tenderness to palpate scale (0-2), AAS = acute ankle sprain) * = significant differences between time points.

Cohen’s AAS (n=46) CON (n=52) p-value d ATFL thickness, mm 2.1 ± .49* 1.8 ± .11* <.001 .84 Pain, VAS, cm .17 ± .57* .00 ± .00* .03 .42 Pain, TTP .55 ± .66* .00 ± .00* <.001 1.17 Table 3.2: ATFL thickness and Pain by Group, all Grades at 6-months.

I (n=22) II (n=25) III (n=5) p-value ATFL thickness, mm 2.2 ± .4* 2.1 ± .2 2.1 ± .2* .003 Pain, VAS, cm 2.1 ± 1.9 .93 ± 1.4 .23 ± .67 .54 Pain, TTP 1.4 ± .70 .82 ± .70 .48 ± .60 .09

Table 3.3: ATFL thickness and Pain in AAS by Grade at 24-72 hours.

I (n=22) II (n=27) III (n=6) p-value ATFL thickness, mm 2.2 ± .4* 2.1 ± .2* 2.1 ± .2 .013 Pain, VAS 2.1 ± 1.9 .93 ± 1.4 .23 ± .67 .76 Pain, TTP 1.4 ± .70 .82 ± .70 .48 ± .60 .19 Table 3.4: ATFL thickness and Pain in AAS by Grade at 2-4 weeks.

I (n=16) II (n=24) III (n=6) p-value ATFL thickness, mm 1.9 ± .5 2.2 ± .5 2.3 ± .3 .22 Pain, VAS, cm .06 ± .25* .08 ± .41* .83 ± 1.2* .007 Pain, TTP .47 ± .74 .52 ± .60 .83 ± .75 .52

Table 3.5: ATFL thickness and Pain in AAS by Grade at 6-months. Mean ± SD (mm= millimeters, ATFL = anterior talofibular ligament, VAS = visual analog scale (0- 10 centimeters, cm), TTP = tenderness to palpate scale (0-2), AAS = acute ankle sprain) * = significant differences between grades.

Discussion The long-term effects of an acute lateral ankle sprain on ATFL thickness have not been identified in this specific population compared to a healthy, uninjured cohort. The purpose of the current study was to examine the difference in thickness of the ATFL in a college-aged population over time after an AAS. At 6-months following an acute LAS, the AAS group had increased ATFL thickness compared to CON. During the first 24-72 hours, a significant difference in ATFL thickness between Grade I and Grade III was evident. At 2-4 weeks, a significant difference in ATFL thickness between Grade I and Grade II was present.

ATFL Thickness

ATFL thickness was greater in the AAS group compared to CON at 6-months. Between the severity of ankle sprains (Grade I-III), ATFL thickness was significantly different at 24-72 hours between Grade I and Grade III. As Grade III had a thicker ligament at 6-months than Grade I, this may be due to the amount of swelling and inflammation on the ligament at that time. At 2-4 weeks, ATFL thickness was significantly different between Grade I and Grade II. Interestingly, no differences were noted at 6-months between grades, showing that the ligament, despite severity, is remodeling at that time. Musculoskeletal ultrasound has been used in previous research to detect the thickness at the midpoint of the ATFL in healthy, coper, and unstable ankles. Liu et al.22 examined those differences between injured limb of the coper and unstable group compared to the healthy group. The ATFL of the injured limb for the coper group

(2.20 ± 0.47 mm, p = .015) and injured limb for the unstable groups (2.28 ± 0.53 mm, p = .015) were thicker than the ATFL of the healthy group (1.95 ± 0.29 mm). The

authors concluded that lasting morphologic changes occurred in those with a previous injury to the ankle, however, the number of previous ankle sprains does not affect the thickness of the ATFL.139 Similarly, we observed that those that sustained an AAS had a thicker ligament than the healthy, CON group (2.1 ± .49 vs 1.8 ± .11 mm, respectively). In the MCL, a study by Sevick et al.26 found differences between reinjured ligaments may have been due to the presence or lack of healing properties and the distance between the ligament ends at time of reinjury. Research is limited to the degree that ATFL thickness changes as the severity of the injury increases. Much of the ATFL is made up of dense fibrous connective tissue with fibroblasts lying between bundles of collagen fibers. Occasional blood vessels were present with a highly vascular synovial membrane lining its deep surface. As the ligament comes under strain in the plantar flexed and inverted position, it increasingly bends around the talar articular cartilage, instead of making the accommodation at the insertion site.16 Thus, potentially changing the morphology and position of the ATFL. When ligaments and their scars are pulled to a certain length and held, they may show a decrease in force or stress with time (stress-relaxation). Ligaments are able to withstand biomechanical testing as early as 2-3 weeks following an injury. Remodeling will occur over the next several months and years.23,24 At this stage, even though the joint function returns, that does not mean that the ligament is healed.23 From the findings of the current study, we know that ligament changes structurally over time and between severity of ankle sprains. This may lead to an increase in scar tissue development well into 6-months post ankle sprain, potentially leading to an incomplete recovery. Middelkoop et al.140 found that those who had not

recovered from an ankle sprain at 3-months follow-up, showed self-reported pain at rest and re-sprains during the first 3 months. These were of prognostic value for recovery at 12 months.

Talar Notch Characteristics In the current study, 49% of the AAS group and 0% of the CON group had the characteristic of a talar notch on the MSUS image. A hypothesis that may lead to why this may show up on the MSUS image is a lesser known injury that can occur to the talus, most commonly in snowboarders, and classified as a talar lateral process fracture. Due to the rapid and forceful motion at the ankle, a varying degree of bone is chipped off, mimicking the pain on palpation similar to a lateral ankle sprain. Even though rare outside of snowboarding, this fracture can be suspected when one has a history of inversion with dorsiflexion ankle sprain mechanism and tenderness upon palpation over the lateral process of the talus. Radiographs are negative up to 40% of the time in these cases.141 Typically, a CT scan is the imaging method of choice, however, sonography has been used in previous research to diagnose the fracture.142 In the case presented by Copercini et al.142, a 32-year-old man had a forceful eversion and external rotation of the ankle during a jump landing while snowboarding the previous day. Symptoms include inability to bear weight, painful ankle swelling, pain with passive inversion and dorsiflexion, while instability tests were inconclusive due to pain. In this case, radiographs were negative, therefore sonography was performed. Sonography was able to detect the fracture, specifically from a longitudinal sonogram over the Achilles tendon showing a hypoechoic area from effusion. Previous research speculates that this fracture can occur from an avulsion due to excessive traction caused by the insertion of the ligaments into the lateral process of

the talus during foot inversion. If untreated, a fracture to the lateral process of the talus can result in nonunion and chronic disability.142 Previous work has also assessed ultrasonography images and classified different types of acute ankle ligament injuries by specific characteristics on the images.28 The authors identified five types: type I whereby the fibular pattern of the ATFL was intact; type II by swelling of the ATFL and fibular pattern intact; type III whereby the fibular pattern of the ATFL is disrupted where the ATFL appears swollen and elongation is evident by application of the anterior drawer (elongation sign); type IV whereby the fibular pattern disrupted and the ATFL tear is complete and unchanged ligament during anterior drawer (floating sign); type V by an avulsion fracture of the edge of the talus or distal lateral malleolus.28 As we think of the talar notch that appears on the sonographic images in the present study, the position of this deformity on the talus, in our opinion, may be the location of the lateral process. Since a portion of those in the AAS group had this “talar notch” deformity and none in the CON group had this deformity, one can speculate that this has to do with a lateral ankle sprain and injury to the ATFL. Hawkins143 described three types of lateral process of the talus fractures: type 1- chip fractures not extending to the joints’ surfaces; type 2- intra-articular, noncomminuted fractures; and type 3- comminuted fractures that involve both joint surfaces. If those that have this “talar notch” on the sonographic image, one can speculate that a previous injury may have occurred over that area, potentially “chipping” or avulsing a portion of the talus as the ATFL stretches during rapid inversion/plantar flexion. Musculoskeletal ultrasound or sonography can be used to detect a lateral process of the talus fracture and must be detected soon after the injury so that long-term

disabilities are not incurred. Clinicians may want to incorporate additional imaging techniques, such as sonography, other than radiographs to differentiate the injury if the patient has experienced an acute lateral ankle sprain.

Conclusion At 6-months following an acute LAS, AAS had a thicker ATFL compared to CON. During the first 24-72 hours, Grade III had a thicker ATFL compared to Grade I. At 2-4 weeks, Grade II had a thicker ATFL compared to Grade I. The talar notch appeared on 49% of AAS and 0% of CON group.

Chapter 4

DYNAMIC BALANCE DEFICITS FOLLOWING AN ACUTE LATERAL ANKLE SPRAIN

(Targeted for submission to Journal of Athletic Training)

Introduction Approximately 72% of patients, in a general population, following an ankle sprain reported residual symptoms six to 18 months later. Of those that reported residual symptoms, 40% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Factors that were associated with moderate to severe symptoms were re-injury of the ankle, activity restriction longer than one week, and limited weight bearing longer than 28 days.10 Previous research has shown that approximately 30% of patients suffering an initial ankle sprain will develop chronic ankle instability.11 Chronic ankle instability (CAI) is defined by those that have suffered recurrent ankle sprains, may have prolonged symptoms, and may exhibit mechanical and/or functional instability.30 Functional deficits have been seen in those with CAI, specifically to postural control or dynamic balance.95,128–131 While several purported reasons exist for these deficits, of particular interest is the difference in dorsiflexion range-of-motion between the injured and uninjured ankles. This can lead to asymmetries between the sides, thus increasing the risk for injury to the ankle. Deficits in dynamic balance with the Y Balance Test (YBT) have been reported in the anterior

reach direction between the injured and uninjured sides, in those with CAI.100,144 Impairments in dynamic balance have clearly been identified as potential predictors of a subsequent ankle sprain, especially in those with CAI. After an acute lateral ankle sprain, dynamic balance deficits have also been previously identified 1, 7, and 21 days after injury.145 Balance impairments, using the Star Excursion Balance Test (SEBT) have also been noted after a first time ankle sprain, specifically in the anterior direction.146 Even though previous research has primarily used the SEBT, differences in methodology of the SEBT and YBT have been identified.97,99 The SEBT involves dynamic and static balance tasks as the subject is asked to reach the opposite limb to its furthest reach distance while maintaining single-limb balance.147,148 The same is asked of the subject in the YBT; however, the difference is with the reaching leg. The subject in the SEBT may touch down their foot in order to measure the distance and regain their balance after. In the YBT, the subject may not touch down or regain their balance with a double-limb stance. They must maintain single-limb balance throughout 3 continuous trials. Thus, making the YBT challenging to the sensorimotor system and a dynamic task. It has been shown to be a valid and reliable dynamic balance task, especially used in an athletic population.97 After an acute ankle sprain, it is unknown whether dynamic balance using the YBT would be affected after the injury later than 21 days. Therefore, the purpose of this study was to investigate dynamic balance deficits in a college-aged population over time after an acute ankle sprain. H4.1 Y Balance Test (YBT) composite scores would be significantly different in the AAS group in the 2-4-week time point compared to the 6-month time point.

H4.2 Despite ankle sprain severity, YBT reach distance asymmetries would be greater in the 2-4-week time point compared to the 6-month time point. H3.3 A relationship between anterior (ANT) reach distance and WBLT will exist across all grades between injured and uninjured ankles.

Experimental Design This study utilized a post-test only design. The independent variables were time (2, 3), injury severity (I, II, III), and group (AAS, CON). The dependent variables were YBT composite (COMP) score (%), relative anterior (ANT) reach distance (%), ANT reach asymmetry (cm), relative posteromedial (PM) reach distance (%), PM reach asymmetry (cm), relative posterolateral (PL) reach distance (%), PL reach asymmetry (cm) (Figure 4.1). Covariates were sex, height, limb length, and mass. Testing took take place at two time points following the injury for the AAS group: 2-4 weeks and 6 months. The CON group was tested on one day only, around the time of the 6-month time point in the AAS group.

Figure 4.1: Experimental Design for Chapter 4.

Participants One hundred and eight volunteers (58 females, 50 males) were recruited for this study. All participants were university student-athletes, recreational or competitive, (Table 2.1), participating in physical activity for at least 30 minutes three times a week. Subjects were further divided into the AAS and CON groups with 55 subjects in the AAS group and 53 subjects in the CON group. (Figure 4.1) For the AAS group, all data were collected on unilateral acute ankle sprains, using the IAC definition of “ankle sprain,” within the first 24-72 hours of injury. 132 Of the AAS group, the participants were categorized depending on injury classification (Grade I, II, III). The involved limb for the AAS group, as well as approximate height and weight, were matched in the CON group. According to the IAC guidelines for CON subjects, the CON group had no history of previous ankle sprains, bilaterally, with a CAIT and IdFAI score of 30 and 0, respectively.132 Participants were excluded from the study if they had CAI bilaterally (CAIT < 24 or IdFAI > 11), were currently seeking treatment for a separate lower extremity injury not including an ankle sprain, or have undergone any lower extremity surgery within the last year.

Instrumentation

Dynamic balance was measured using the YBT. The YBT consisted of a single-leg balance task while the opposite leg slides a block to a maximal reach distance in three different directions (anterior- ANT, posteromedial- PM, posterolateral- PL). The subject’s limb length (LL) was measured using a tape measure from ASIS to the most distal portion of the medial malleolus. In each reach direction, the limb length will be used to determine the relative reach distance (%) [(greatest of ANT or PM or PL/ LL)* 100]. A composite score relative to limb length

was calculated (Figure 4.2). Reach distance asymmetries were calculated by subtracting the maximal reach for the uninvolved limb and involved limb for each direction (ANTdiff, PMdiff, PLdiff).For the WBLT and DF ROM, an inclinometer/protractor and tape measure were used.

X 100

Figure 4.2: Y Balance Test Composite Score (%) Equation.

Procedures

Demographic and Anthropometric Data

Participants completed an inclusion questionnaire (Appendix B) containing general information such as age, height, weight, and previous lower extremity injury history. They also completed three separate surveys related to foot and ankle function and instability to determine if any of the subjects fall into CAI status, which would exclude them from this study. The three surveys included were the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports Subscales (Appendix C), Cumberland Ankle Instability Tool (CAIT) (Appendix D), and Identification of Functional Ankle Instability (IdFAI) (Appendix E).117

Injury Classification To determine injury severity/grade, DF ROM using a goniometer, ankle girth (edema) using a tape measure in a figure-of-eight method, and laxity measured by the

TI was performed. Table 2.2 represents the methods described by Malliaropoulos et al.27 to classify ankle sprain grade.

Y Balance Test The methodologies described by Plisky et al.97 and the Functional Movement Screen96 directions were used to perform the YBT for this study. The participant was bare foot and limb length was measured, in centimeters, for both limbs prior to testing. Limb length was defined as the distance from the anterior superior iliac spine to the most distal portion of the medial malleolus. The participant was instructed on how to complete the test by demonstrating each reach direction, where to place each foot, and to maintain continuous single-limb balance throughout the three trials for each limb in each direction. The three reach directions are anterior (ANT), posteromedial (PM), and posterolateral (PL) (Figure 4.3). The participant was instructed to stand in the center of the footplate with the distal part of their right foot at the start of the red line. While maintaining balance on the right stance leg, which was the leg being measured, the opposite left foot slid the indicator box from behind as far forward as possible, while maintaining contact with the box always. Three consecutive trials were performed with the right limb in the anterior direction and then with the left limb in the anterior direction. This same progression was repeated for the PM and PL directions. Attempts were rejected and repeated if the athlete failed to maintain unilateral stance on the platform, failed to maintain contact with the indicator box with the reach foot, placed the toes or foot on top of the indicator box, touched the ground or testing poles with the reach foot, or failed to return the reach foot back to the starting position under control without touching the ground. Athletes were given a maximum of six attempts to achieve three successful trials. If there were more than

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four failed attempts, a zero was recorded for that trial. Maximal reach distances were recorded by reading the measurement at the edge of the reach indicator box to the nearest 0.5 cm, relative to the participant’s limb length. Composite scores were calculated for each the right and left limbs to provide an overall performance rating relative to one’s body. This overall score took the sum of the greatest reach distances in all three directions divided by three times the limb length, and then multiplied by 100 (Figure 4.2).96,97,149

Figure 4.3: Y Balance Test. (a) Anterior (b) Posteromedial (c) Posterolateral reach directions.

Weight-Bearing Lunge Test The WBLT was administered using the methodology described by Bennell et al.85 The ROM in degrees and the distance away from the wall in centimeters were collected. Three trials were done with the maximal range-of-motion used for analysis. If the participant easily reached the wall with their toes at 10 cm, the trial was redone at a further distance 1 cm at a time until the maximal distance and range was achieved. The same was done if the participant was unable to touch the wall without their heel rising at 10 cm. The foot moved closer to the wall 1 cm at time until their maximal

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distance and range was achieved. The inclinometer was placed on the participant’s anterior distal tibia.

Statistical Analysis To answer the proposed aim, the following statistical analyses were employed: 1) paired-samples t-test to analyze the YBT for the AAS group over the two-time points (2-4 weeks, and 6 months); 2) independent sample t-tests to compare the variables across the two groups (AAS and CON) at the 6-month time point; 3) one- way ANOVA to compare the variables across the three grades of severity (Grade I, Grade II, Grade III) in AAS during the three time points; 4) a linear mixed model to analyze the dependent variables between injured and uninjured ankles across time; 5) Pearson’s correlation coefficient to determine the relationship between WBLT and ANT reach distance. Cohen’s d effect sizes were reported to determine the standardized difference in the means of significant findings. A small effect size was represented by 0.2, medium by 0.5, and large as 0.8. All data were analyzed using the Statistical Package for Social Sciences Version 25 (SPSS, Chicago, IL). An a priori alpha level of .05 was used to denote statistical significance.

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Results The results of the study are presented by dependent variable and further by analysis. Each variable of the YBT (ANT, PM, PL, COMP, ANT diff, PM diff, PL diff, COMP diff) was assessed in AAS group over time, by group at 6-months, by ankle sprain severity over time, and between ankles in the AAS group.

YBT

AAS Over Time Between the second and third time points, there was a significant increase in ANT (p < .001), COMP (p = .005) and a significant decrease in ANT diff (p = .004).(Figure A.8) There were no significant differences were found between time 2 and 3 in PM (p = .210), PM diff (p = .256), PL (p = .106), PL diff (p = .637), and COMP diff (.724). (Table 4.1)

Group at 6-months In comparing the AAS and CON groups at 6-months, there was a difference in

COMP diff (F= 4.296, p = .018) and approaching significant difference for ANT (p = .056). There were no statistical differences in ANT diff, PM, PM diff, and PL, PL diff, and COMP in AAS compared to CON at 6-months.(Table 4.2, Figure A.9)

AAS by Severity

There was a significant increase in ANT diff between Grade I and Grade III (p = .028) at time 2. No significant differences were observed at time 2 between ANT, PM, PM diff, PL, PL diff, COMP or COMP diff. (Table 4.3) At time 3, there were no significant differences between severity for ANT, ANT diff, PM, PM diff, PL, PL diff, COMP, and COMP diff. (Table 4.4)

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AAS Over Time Between Ankles Significant differences were noted at time 2 in ANT (p < .001), PM (p = .05), PL (p < .001), and COMP (p < .001). Significant differences were observed at time 3 in PL (p = .046) and COMP (p < .001). At time 3, no significant differences were found in ANT (p = .161), and PM (p = .630).

YBT/WBLT Correlation

A relationship existed between WBLT and ANT in the 6-month time point in the AAS group (.376, p= .034).

2 3 Cohen’s p-value 2-4 weeks 6-months d ANT, % 53.3 ± 6.5 57.5 ± 6.8 < .001 .63 PM, % 98.4 ± 10.9 99.9 ± 11.2 .21 PL, % 92.2 ± 11.1 94.6 ± 11.5 .11 COMP, % 81.3 ± 7.7 84.0 ± 8.1 .005 .34 ANT diff, % 5.2 ± 3.8 3.2 ± 3.3 .004 .39 PM diff, % 4.7 ± 3.6 3.8 ± 3.3 .26 PL diff, % 5.9 ± 5.1 5.4 ± 4.0 .64 COMP diff, % 3.7 ± 4.3 3.4 ± 2.7 .72 Table 4.1: Y Balance Test Scores in AAS Over Time.

Mean ± SD (ANT = anterior, PM = posteromedial, PL = posterolateral (cm, centimeters), COMP = composite (percentage, %), diff = difference between limbs, AAS = acute ankle sprain)

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AAS (n=46) CON (n=52) p-value Cohen’s d ANT, % 57.5 ± 6.8 60.6 ± 9.9 .056 .36 PM, % 99.9 ± 11.2 97.5 ± 14.5 .35 PL, % 94.6 ± 11.5 91.4 ± 19.1 .31 COMP, % 84.0 ± 8.1 83.3 ± 12.2 .75 ANT diff, % 3.1 ± 3.3 2.4 ± 2.1 .17 PM diff, % 3.8 ± 3.4 3.8 ± 2.9 .94 PL diff, % 5.4 ± 4.0 4.0 ± 3.2 .06 COMP diff, % 3.4 ± 2.7 2.3 ± 1.8 .018 .47 Table 4.2: Y Balance Test Scores by Group at 6-months.

Mean ± SD (ANT = anterior, PM = posteromedial, PL = posterolateral (cm, centimeters), COMP = composite (percentage, %), diff = difference between limbs, AAS = acute ankle sprain)

I (n=22) II (n=27) III (n=6) p-value ANT, % 53.7 ± 5.6 52.7 ± 6.1 50.1 ± 10.9 .49 PM, % 97.7 ± 10.3 98.6 ± 10.5 96.2 ± 12.8 .88 PL, % 92.2 ± 10.1 92.8 ± 10.2 87.1 ± 13.9 .48 COMP, % 81.2 ± 7.4 81.4 ± 6.9 77.8 ± 10.5 .56 ANT diff, % 4.0 ± 3.1* 5.3 ± 3.9 8.7 ± 5.7* .031 PM diff, % 4.2 ± 3.8 4.9 ± 4.3 5.4 ± 3.0 .76 PL diff, % 4.2 ± 4.5 6.9 ± 5.0 6.3 ± 4.9 .15 COMP diff, % 2.3 ± 3.7 4.3 ± 4.4 5.8 ± 5.9 .18

Table 4.3: Y Balance Test Scores by Grade at 2-4 weeks. Mean ± SD (ANT = anterior, PM = posteromedial, PL = posterolateral (cm, centimeters), COMP = composite (percentage, %), diff = difference between limbs, AAS = acute ankle sprain)

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I (n=16) II (n=24) III (n=6) p-value ANT, % 58.2 ± 7.2 56.0 ± 5.9 61.5 ± 8.2 .19 PM, % 97.8 ± 12.3 99.5 ± 9.6 107.5 ± 13.1 .19 PL, % 95.9 ± 13.1 95.8 ± 10.1 91.5 ± 13.5 .69 COMP, % 83.3 ± 9.4 83.8 ± 6.8 86.8 ± 10.1 .65 ANT diff, % 2.3 ± 1.5 4.1 ± 4.1 1.5 ± 1.6 .11 PM diff, % 2.9 ± 2.3 4.1 ± 2.8 5.5 ± 6.6 .27 PL diff, % 4.9 ± 3.0 5.2 ± 4.5 7.2 ± 4.4 .51 COMP diff, % 2.4 ± 1.8 4.0 ± 3.1 3.7 ± 2.7 .18

Table \4. 4: Y Balance Test Scores by Grade at 6-months. Mean ± SD (ANT = anterior, PM = posteromedial, PL = posterolateral (cm, centimeters), COMP = composite (percentage, %), diff = difference between limbs, AAS = acute ankle sprain)

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Discussion The long-term effects of an acute lateral ankle sprain on dynamic balance using the YBT have not been identified in this specific population compared to a healthy, uninjured cohort. The purpose of the current study was to investigate dynamic balance deficits in a college-aged population over time after an acute ankle sprain. Between 2-4 weeks and 6-months following an acute lateral ankle sprain, YBT scores (ANT and COMP) improved. By severity at 2-4 weeks, ANT diff was greater in those with a Grade III ankle sprain vs a Grade I. A significant relationship exists between WBLT and ANT reach in the AAS group at 6-months.

YBT

The Y Balance Test (YBT), which was developed by Functional Movement Systems96 and described by Plisky et al.97, is a reliable dynamic balance assessment tool involving the participant to maintain single-limb balance while sliding an indicator with the opposite limb. Butler et al. identified a cut-off point of 89.6% for the composite score on the YBT with a sensitivity of 100% and specificity of 71.7%. Within that study, a college football player who scored below 89.6% was 3.5 times more likely to obtain a noncontact lower extremity injury.98 Female athletes that score <94% of their limb length are 6.5 times as likely to sustain a musculoskeletal injury. Asymmetry in the reach distances have been investigated previously.100,101 In the anterior reach, an observable difference > 4 cm between the limbs is associated with an elevated risk of injury.99 Where in the present study, the average of the difference in anterior reach exceeded 4 cm in all grades at 2-4 weeks post-AAS. As the asymmetry between the involved and uninvolved limbs in the ANT direction was greater in Grade III and that a relationship exists between WBLT and ANT reach, this

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difference may be directly tied to the deficit in DFROM in those with a Grade III ankle sprain. Conclusions from previous research is mixed on whether a deficit in DFROM over time may lead to a subsequent ankle sprain. Further research is needed to confirm this conclusion.78,79,150 Our results show a significant increase in ANT and COMP over time. This improvement from 2-4 weeks and 6-months post-AAS is likely due to an added focus on balance tasks during rehabilitation. Previous research has found after a 4-week balance training using the SEBT, improvements in the PM and PL reach were obtained.151,152 McKeon et al. found after a review of the effectiveness of balance training, that completing at least 6 weeks of balance training after an acute ankle sprain substantially reduced the risk of recurrent ankle sprains.152 Even though current research focuses heavily on the anterior reach as a risk factor, de Noronha et al.79 reported that subjects with better posterolateral performance on the SEBT were less likely to suffer an ankle sprain. With a SEBT PL reach under 80, participants have a 48% greater risk of suffering a sprain; however, 90% of their limb length or higher, had a significantly lower incidence of sprains.79 A potential reason for this deficit in PL reach leading to a subsequent ankle sprain, the authors concluded, may be due to the pattern of muscle activation during this reach. Similarly, Attenborough et al.113 found that the posteromedial reach in the SEBT of less than or equal to 77% of leg length increased the odds of sustaining an ankle sprain.113 Our results for the PM and PL reach were above 77% and 90%, respectively, in all grades at 2-4 weeks and 6-months post-AAS. (Table 4.3 and 4.4)

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Conclusion Between 2-4 weeks and 6-months following an acute lateral ankle sprain, YBT scores (ANT and COMP) improved. This improvement may be seen due to the increase in dynamic balance exercises during the rehabilitation process and return to full participation. By severity at 2-4 weeks, ANT diff was greater in those with a Grade III ankle sprain vs a Grade I. Those with a Grade III ankle sprain may still have an altered ligament and presence of swelling at the 2-4 week time point compared to a Grade I. A significant relationship exists between WBLT and ANT reach in the AAS group at 6-months. If the WBLT decreases over time, ANT diff may increase. It is important, as clinicians, to watch and detect differences in range of motion of the ankle, as they can correlate to functional measures, even if they have already returned to play.

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Chapter 5

TALOFIBULAR INTERVAL, ATFL THICKNESS, AND DYNAMIC BALANCE

(Targeted for submission to Journal of Athletic Training)

Introduction Within an athletic population, 27-34% of all musculoskeletal injuries occur to the foot and ankle.7,8 Ankle sprains have been reported as the most common injury in 77% of all ankle injuries in sport. Lateral ankle sprains are the most commonly observed type of ankle sprain.9 Of the 73% that reported residual symptoms following an ankle sprain, 40.4% reported at least one moderate to severe symptom, which included: perceived ankle weakness, perceived ankle instability, pain, and swelling. Factors that were associated with moderate to severe symptoms were re-injury of the ankle, activity restriction longer than one week, and limited weight bearing longer than 28 days.10 Approximately 30% of patients suffering an initial ankle sprain will develop chronic ankle instability.11 Chronic ankle instability (CAI) is defined by those that have suffered recurrent ankle sprains, may have prolonged symptoms, and may exhibit mechanical and/or functional instability.30 Functional deficits have been seen in those with CAI, specifically to dynamic balance and range-of-motion.95,128–131 Thompson et al.13 reported independent prognostic factors of poor recovery after an acute lateral ankle sprain to include: age, female gender, swelling, restricted range-of-motion, limited weight-bearing ability, pain (at the medial joint line and on

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weight-bearing dorsiflexion at 4 weeks, and pain at rest at 3 months), higher injury severity rating, palpation/stress score, non-inversion mechanism injury, lower self- reported recovery, re-sprain within 3 months, MRI determined number of sprained ligaments, severity and bone bruise. However, there is insufficient evidence to recommend any specific factor as an independent predictor. The following indicators of interest to consider over time after an acute lateral ankle sprain are: dorsiflexion range-of-motion, ankle laxity, ATFL thickness, pain, dynamic balance, and ankle function. A reduction in dorsiflexion range-of-motion (ROM) after an ankle sprain has been identified as a strong injury predictor, leading to a subsequent ankle sprain. 76,78– 80 Previous research has determined that this deficit may result from an anterior displacement of the talus or loss of posterior talar glide.77 As deficits in range-of- motion occur after an ankle sprain, deficits in talocrural, ankle joint, laxity also occur.111,136 These deficits in anterior drawer and talar tilt/ inversion have been noted after acute ankle sprains and in those with CAI using stress devices.40,153,154 The manual stress tests are performed by clinicians at the time of injury to determine severity. However, the reliability of performing these tests with a measurable amount of force is limited.40,70,155 Ankle joint laxity has been noted to be increased over time after an ankle sprain, especially in inversion.37,43,136 Following a lateral ankle sprain, the anterior talofibular ligament (ATFL) is primarily involved with stretching or tearing occurring at the ligament.17,30 Ligament thickness of the ATFL, using musculoskeletal ultrasound, has been previously reported to be increased in those with a history of previous ankle sprains and those with greater ankle instability, however, the number of repeated ankle sprains did not

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have an impact on ATFL thickness.22,139 It is unknown as to how ligament thickness changes over time after an acute ankle sprain and if the severity of the ankle sprain may affect the ligament thickness, compared to a healthy and CAI cohort. van Rijn et al. identified that patients reported a rapid decrease in pain within the first two weeks of injury. One year after an acute lateral ankle sprain, 5% to 33% of patients still experienced pain, while 36% to 85% reported full recovery within a three-year period. The risk of re-sprain that was reported in patients was wide (3% to 34%), with the re-sprain occurring over a period from two weeks to 96 months’ post- injury.11 Self-reported pain is an important indicator for the healing of an ankle sprain and if the severity of the ankle sprain may affect the amount of pain over time. Dynamic balance deficits have been noted in those with functional instability and are associated with the amount of time in balance and the number of foot lifts.95 The Y Balance Test (YBT), as described by Plisky et al.97, is a reliable dynamic balance assessment tool involving the participant to maintain single-limb balance while sliding an indicator with the opposite limb. Butler et al. identified a cut-off point of 89.6% for the composite score on the YBT, which for a male is 3.5 times more likely to obtain a noncontact lower extremity injury.98 Asymmetry in the reach distances have been investigated previously.100,101 In the anterior reach, an observable difference > 4 cm between the limbs is associated with an elevated risk of injury.99 The MCID for the YBT composite score has been previously reported as 3.5%, relative to limb length.101,102 Recently, previous research has identified that those with perceived instability, have less health-related quality of life and more functional limitations compared to healthy, uninjured participants.119 Besides the potential for degenerative joint changes,

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those that sustain an ankle sprain may see long-term effects to their overall health if not treated appropriately.54 Self-reported physical activity deficits have been reported one year after an acute ankle sprain.120 During the initial assessment, clinicians will grade the ankle sprain depending upon the severity of the injury and the symptoms presented. Manual stress tests, such as, the anterior drawer and talar tilt tests, are employed. However, these tests have been shown to be less reliable in determining stability of the talocrural joint, thus making the clinical decision of injury severity less accurate.40 This can be challenging, since severity plays a significant role in the clinician’s decision-making for rehabilitation and time to return-to-play. This leads us to question, if we, as clinicians, inaccurately grade an acute ankle sprain and return these athletes to play too quickly, will they end up developing symptoms that could lead to CAI? Thus, it is important to grade an acute ankle sprain immediately after it has happened, note any deficits that occur and when they are able to return-to-play, and then follow the athlete after the injury to determine if deficits still occur that could lead to CAI. Therefore, the overall purpose of the current study was to compare dorsiflexion range-of-motion, ankle laxity, ATFL thickness, pain, dynamic balance, and ankle function in a college-aged population that has experienced an acute ankle sprain and compare to those that present with CAI and those without a history of previous ankle sprains. H5.1 We hypothesized that the AAS group would be significantly different than CON at the 6-month period.

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H5.2 We hypothesized that there would be no significant differences between the AAS group and the CAI group at 6 months post-injury in mechanical laxity, ATFL thickness and dynamic balance.

Experimental Design This study utilized a post-test only design. The independent variables were time, injury severity (I, II, III), and group (AAS, CON). The dependent variables included: AD/INV TI and stress (mm), ATFL thickness (mm), YBT composite (COMP) score (%), COMP asymmetry (COMP diff), relative anterior (ANT) reach distance (%), ANT reach asymmetry (ANT diff) (cm), relative posteromedial (PM) reach distance (%), PM reach asymmetry (PM diff) (cm), relative posterolateral (PL) reach distance (%), PL reach asymmetry (PL diff) (cm). (Figure 5.1) Covariates were sex, height, limb length, and mass. Testing took place at three time points following the injury for the AAS group: (1) 24-72 hours, (2) 2-4 weeks, and (3) 6-months. The CAI and CON groups were tested on one day only, around the time of the 6-month time point in the AAS group.

Figure 5.1: Experimental Design for Chapter 5.

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Participants One hundred and sixty-one volunteers (96 females, 65 males) were recruited for this study. All participants were university student-athletes, recreational or competitive participating in physical activity for at least 30 minutes three times a week. (Table 5.1) Subjects were divided into the AAS (55), CON (53) and CAI (53) groups. (Figure 5.1). For the AAS group, all data were collected on unilateral ankle sprains, using the IAC definition of “ankle sprain,” within the first 72 hours of injury.132 Of the AAS group, the participants were categorized depending on injury classification (Grade I, II, III). According to the IAC guidelines for CON subjects, these subjects had no history of previous ankle sprains, bilaterally, with a CAIT and

IdFAI score of 30 and 0, respectively. 132 The CAI group followed the IAC guidelines as: a history of at least one significant ankle sprain, history of previously injured ankle joint “giving way” and/or recurrent sprain and/or “feelings of instability” with a CAIT < 24 and IdFAI > 11, and a general self-reported foot and ankle function questionnaire to determine the level of disability (FAAM, ADL < 90%, Sport < 80 %).117 Participants were excluded from the study if they were currently seeking treatment for a separate lower extremity injury not including an ankle sprain or had undergone any lower extremity surgery within the last year.

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AAS (n = 55) CON (n = 53) CAI (n = 53) N = 161 27 F/ 28 M 31 F/ 22 M 38 F/ 15 M 96 F/ 65 M

Age, yrs. 20.4 ± 1.9 Age, yrs. 20.3 ± 1.7 Age, yrs. 20.5 ± 1.5 Age, yrs. 20.4 ± 1.7

116 Height, cm 175.9 ± 12 Height, cm 169.3 ± 10.1 Height, cm 170.5 ± 10.5 Height, cm 172.0 ± 11.2

Mass, kg 77.4 ± 15.1 Mass, kg 68.8 ± 13.3 Mass, kg 71.9 ± 16.4 Mass, kg 72.8 ± 15.4 Table 5.1: Participant Demographics for Chapter 5. Mean ± SD. Acute Ankle Sprain (AAS), Control (CON), Chronic Ankle Instability (CAI), years (yrs), centimeters (cm), kilograms (kg), female (F), male (M).

Instrumentation Mechanical laxity of the talocrural joint was measured by stress ultrasonography using the LigMaster (LigMaster Inc., Charlottesville, VA, USA) to stress the ankle in INV and AD positions, while taking an ultrasound image measured by musculoskeletal ultrasound (MSUS) using a GE logiq e (General Electric Company, Waukesha, WI, USA) at a 12 MHz frequency and 2.5 cm depth. The transducer head was positioned in the sinus tarsi, obliquely from the distal fibula from the origin to insertion of the ATFL.22 Ultrasonic gel (Aquasonic 100, Parker

Laboratories, Inc. Fairfield, NJ) was used as a conductive medium for the sound waves to travel from the probe through the skin. INV and AD stress was defined as the distance between the peak of the talus and fibula at the maximal stress position. INV and AD TI was defined as the difference between stress and static measures. Interrater reliability of the LigMaster joint arthrometer has been previously reported for the talar inversion and anterior drawer tests as 0.76 and 0.81, respectively.41 Intrarater reliability of the LigMaster for talar inversion and anterior drawer test were 0.74 and 0.65, respectively.41 For the WBLT and DF ROM, an inclinometer/protractor, goniometer, and tape measure were used. Thickness of the ATFL was measured by

MSUS at a 12 MHz frequency and 2.5 cm depth. The position of the transducer head was positioned in the sinus tarsi, obliquely from the distal fibula from the origin to insertion of the ATFL.22 Reliability of this measure has been previously reported by Liu et al. (ICC= 0.91).22 Dynamic balance was measured using the YBT. The YBT consisted of a single-leg balance task while the opposite leg slides a block to a maximal reach distance in three different directions. The subject’s limb length was

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measured using a tape measure from ASIS to the most distal portion of the medial malleolus. In each reach direction, the limb length will be used to determine the relative reach distance (%) [(greatest of ANT or PM or PL/ LL)* 100]. A composite score relative to limb length was calculated (Figure 4.2). Reach distance asymmetries were calculated by subtracting the maximal reach for the uninvolved limb and involved limb for each direction (ANTdiff, PMdiff, PLdiff).

Procedures

Demographic and Anthropometric Data

Participants completed an inclusion questionnaire (Appendix B) containing general information such as age, gender, height, weight, and previous lower extremity injury history. They also completed three separate surveys related to foot and ankle function and instability to determine if any of the subjects fall into CAI status, which would exclude from the study. The three surveys included are the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports Subscales (Appendix C), Cumberland Ankle Instability Tool (CAIT) (Appendix D), and Identification of Functional Ankle Instability (IdFAI) (Appendix E).117 The results of each questionnaire previously mentioned was included for analysis to determine differences in ankle function across the groups.

Injury Classification To determine injury severity/grade, DF ROM using a goniometer, ankle girth (edema) using a tape measure in a figure-of-eight method, and laxity measured by the TI was performed. Table 2.2 represents the methods described by Malliaropoulos et al.27 to classify ankle sprain grade.

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Pain At the beginning of each testing session, the participant was asked using a Visual Analog Scale (VAS) of 0 to 10 centimeters to report their pain at that current moment in each ankle, where 0 = no pain and 10 = unbearable pain. The next pain measure was a subjective clinical outcome of tenderness to palpate (TTP) over the sinus tarsi. A TTP scale was created from 0 to 2, where 0 would be no pain/discomfort compared to the other ankle, 1 would be a mild, dull discomfort, and 2 would be a sharp pain, compared to the other ankle. The TTP was collected while palpating both ankles at the sinus tarsi, simultaneously.

Statistical Analysis

A one-way ANOVA was utilized to compare ROM, laxity, ATFL thickness, pain, dynamic balance, and ankle function (previous ankle sprains, IdFAI, CAIT, FAAM-ADL, FAAM-Sport) across the three groups (AAS, CON, and CAI) at the 6- month time point. A post-hoc analysis involved the Tukey method. Cohen’s d effect sizes were reported to determine the standardized difference in the means of significant findings. A small effect size was represented by 0.2, medium by 0.5, and large as 0.8. All data were analyzed using the Statistical Package for Social Sciences Version 25 (SPSS, Chicago, IL). An a priori alpha level of .05 was used to denote statistical significance.

Results The results of the study are presented by dependent variable (range-of-motion, laxity, ATFL thickness, pain, balance, and ankle function) and were assessed across all three groups (AAS, CON, and CAI). Significant differences between the groups from the post-hoc are provided.

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ROM There were significant differences between groups in DFROM (F= 4.102, p= .018) (Figure A.10), where significant decrease was noted between CON and CAI (p= .016, 95% CI: .30—3.89). No significant differences were observed between groups in WBLT cm (p = .184), WBLT deg (p = .117). (Table 5.2)

Laxity

There were significant differences between groups in INV stress (F = 15.400, p < .001), INV TI (F = 6.031, p = .003), and AD stress (F = 7.384, p = .001) (Figure A.11). For INV stress, significant differences existed between AAS and CON (p < .001, 95% CI: 1.47—4.32) and AAS and CAI (p < .001, 95% CI: 1.39—4.22). For INV TI, significant differences existed between AAS and CON (p= .006, 95% CI: .379—2.83), AAS and CAI (p= .013, 95% CI: .239—2.67). In AD stress, significant differences were between AAS and CON (p = .002, 95% CI: .632—3.65) and AAS and CAI (p = .004, 95% CI: .541—3.54). No significant differences were observed between groups in AD TI (p =.442). (Table 5.2)

ATFL Thickness There were significant differences between groups in ATFL thickness (F= 10.576, p < .001) (Figure A.12), between AAS and CON (p < .001, 95% CI: .147—

.511), CON and CAI (p = .003, 95% CI: .066—.415). (Table 5.2)

Pain There were significant differences between groups (AAS, CON, and CAI) for VAS Pain (F = 11.914, p < .001) and TTP (F= 39.497, p < .001). After a Tukey post hoc analysis, differences between specific groups were determined. For pain, VAS, a

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significant difference existed between AAS and CAI (p= .004, 95% CI: .11—.76), CAI and CON (p < .001, 95% CI: .30—.92). For TTP, significant differences existed between AAS and CON (p < .001, 95% CI: .27—.82), CON and CAI (p < .001, 95% CI: .69—1.20) and AAS and CAI (p = .002, 95% CI: .13—.67). (Table 5.2)

Balance There were significant differences between groups in ANT (F= 3.347, p= .038), PM (F= 3.227, p= .042), and COMP (F= 3.146, p = .046). (Figure A.13) For ANT, a significant difference existed between CON and CAI (p= .049, 95% CI: .013—7.43). For PM, a significant difference existed between AAS and CAI (p= .041,

95% CI: .191—12.89). No significant differences were observed between groups in ANT diff (p = .242), PM diff (p = .087), PL (p = .057) PL diff (p = .164), COMP (p = .075) and COMP diff (p = .096). (Table 5.2)

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p- Cohen’s Group (6-months) AAS (n=46) CON (n=54) CAI (n=54) value d Girth, cm 49.3 ± 3.9 48.5 ± 3.0 48.6 ± 4.0 .56 DFROM, deg 9.9 ± 3.6 10.6 ± 3.9* 8.5 ± 3.9* .018 .54 WBLT, cm 8.8 ± 3.6 9.8 ± 3.6 8.6 ± 3.1 .18 WBLT, deg 42.4 ± 8.3 44.9 ± 10.1 41.5 ± 7.5 .12

AD Stress, mm 22.7 ± 3.6* 20.6 ± 2.8* 20.7 ± 2.9* .001 .65/.61 INV Stress, mm 22.3 ± 3.1* 19.4 ± 2.9* 19.5 ± 2.7* < .001 .96 AD TI, mm 1.0 ± 2.1 .53 ± 1.7 .81 ± 1.7 .44 INV TI, mm .72 ± 2.5* -.88 ± 2.4* -.73 ± 2.5* .003 .65/.58

ATFL thickness, < .001 .86/.66 mm 2.1 ± .48* 1.8 ± .11* 2.0 ± .41*

Pain, VAS, cm .17 ± .57 .00 ± .00 .61 ± .99 < .001 .42/.87 Pain, TTP .55 ± .66* .00 ± .00* .94 ± .71* < .001 1.17/1.87

ANT, % 57.5 ± 6.8 60.6 ± 8.9* 56.9 ± 7.8* .038 .39/.44 PM, % 99.9 ± 11.2* 97.5 ± 14.5 93.4 ± 12.9* .042 .54 PL, % 94.6 ± 11.5* 91.4 ± 18.1 87.1 ± 15.9* .060 .54 COMP, % 84.0 ± 8.1* 83.3 ± 12.2 79.1 ± 11.2* .046 .50 ANT diff, % 3.2 ± 3.3 2.4 ± 2.1 3.2 ± 2.4 .24 PM diff, % 3.8 ± 3.4 3.8 ± 2.9 5.2 ± 4.1 .08 PL diff, % 5.4 ± 4.0 4.0 ± 3.3 4.7 ± 3.5 .16 COMP diff, % 3.4 ± 2.7 2.3 ± 1.7 2.2 ± 4.2 .09

Table 5.2: Injury Classification, Ankle Laxity, ATFL Thickness, Pain, and YBT scores by Group at 6-months. Mean ± SD (deg = degrees, mm = millimeters, VAS = visual analog scale (0-10), TTP = tenderness to palpate scale (0-2), ANT = anterior, PM = posteromedial, PL = posterolateral (cm, centimeters), COMP = composite (percentage, %), diff = difference between limbs, AAS = acute ankle sprain, CON = control, CAI = chronic ankle instability, *= significant differences between groups at p < .05)

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Ankle Function In terms of previous number of ankle sprains in each group, there were significant differences between AAS and CON (p < .001, 95% CI: 1.25—3.08), AAS and CAI (p = .034, 95% CI: .06—1.88), and CON and CAI (p < .001, 95% CI: 2.21— 4.06). (Figure A.14) There were significant differences between groups for IdFAI at time 3 between AAS and CON (p < .001, 95% CI: 11.10—17.13) and between AAS and CAI (p < .001, 95% CI: 14.17—19.54). (Figure A.15) However, no differences between CON and CAI were noted (p = .087). There were significant differences between groups for CAIT at time 3 between AAS and CON (p < .001, 95% CI: 2.56— 8.42), AAS and CAI (p < .001, 95% CI: 3.36—9.19), and CON and CAI (p < .001,

95% CI: 9.18—14.35). (Figure A.16) There were significant differences between groups for FAAM-ADL at time 3 between AAS and CAI (p = .018, 95% CI: .74— 10.59) and between CON and CAI (p < .001, 95% CI: 5.40—14.21). However, no differences were noted between AAS and CON (p = .131). (Figure A.17) There were significant differences between groups for FAAM-Sport at time 3 between AAS and CON (p < .001, 95% CI: 2.13—6.30), AAS and CAI (p = .012, 95% CI: .44—4.62), and CON and CAI (p < .001, 95% CI: 4.88—8.61). (Table 5.3, Figure A.18)

p- Cohen’s Group AAS CON CAI value d Previous Ankle < .001 1.4/1.7 Sprains 2.2 ± 2.2* 0.0 ± 0.0* 3.1 ± 2.5* IdFAI 16.6 ± 6.4* 2.5 ± 2.5* 19.2 ± 7.0* < .001 2.9/3.1 CAIT 23.3 ± 6.5* 28.8 ± 1.2* 17.1 ± 6.8* < .001 1.2/2.4 FAAM-ADL 79.3 ± 10.8* 83.5 ± 1.4* 73.7 ± 12.0* < .001 .54/1.1 FAAM-Sport 27.6 ± 4.7* 31.8 ± .66* 25.1 ± 5.0* < .001 1.3/1.8

Table 5.3: Subjective Ankle Function Questionnaire Scores by Group at 6-months. Mean ± SD (IdFAI = Identification of Functional Ankle Instability, CAIT = Cumberland Ankle Instability Tool, FAAM = Foot and Ankle Measure, ADL = activities of daily living, AAS = acute ankle sprain, CON = control, CAI = chronic ankle instability, *= significant differences between groups at p < .001)

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Discussion The long-term effects of an acute lateral ankle sprain on ankle joint laxity, ATFL thickness, dynamic balance, and ankle joint function have not been previously identified in a college-aged population compared to a healthy uninjured cohort and in a cohort with CAI. The primary findings were that differences exist between the groups in range-of-motion, mechanical laxity, ATFL thickness, pain, dynamic balance, and ankle function. Those who experienced an AAS had increased laxity compared to CON and CAI. Whereas, AAS and CAI each had greater ATFL thickness than CON. Additionally, those with CAI had less range-of-motion and balance than CON. In terms of ankle function, the CAI had a greater number of previous ankle sprains and worse scores on questionnaires for ankle function and instability, than AAS and CON.

Range-of-Motion

A significant decrease in DFROM was noted in those with CAI compared to CON. After an ankle sprain, range-of-motion (ROM) is reduced in dorsiflexion compared to the healthy ankle and has been identified as a strong lower extremity injury predictor.76 This can result from an anterior displacement of the talus or loss of posterior talar glide.77 Those with reduced dorsiflexion ROM (34 degrees) are approximately five times more likely to suffer an ankle sprain compared to those with average range (45 degrees).78 The amount of range of motion or arthrokinematic restriction that occurs at the ankle will depend on the severity of the ankle sprain. During gait, restriction of dorsiflexion ROM may increase the risk of ankle sprains limiting the ankle’s ability to reach a ‘closed-packed’ position during midstance.81 For normal walking, at least 10 degrees of dorsiflexion is required; however, for running,

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20 to 30 degrees of dorsiflexion is required.82 In a jump landing, those with dorsiflexion ROM restriction have less knee flexion and greater ground reaction forces.83 The weight-bearing lunge test (WBLT) has been previously identified as the best measure of DF ROM compared to non-weight bearing goniometric measurements, due to the functional, “closed-packed” position.84 Bennell et al.85 have previously reported the intra-rater ICC ranging from 0.97 to 0.98 and the inter-rater ICC as 0.97 (using an inclinometer) and 0.99 (using distance from the wall in cm). Previous research has identified the causal relationship between dynamic balance tasks and DF ROM.86–89 In those with CAI, decreased DF ROM and anterior Star Excursion Balance Test (SEBT) reach distance has been seen compared to healthy controls.87 A fair positive correlation has been reported between DF ROM and the anterior reach direction (r=.55), posterolateral reach direction (r=.29), and composite SEBT scores (r=.30). Ankle DF ROM can influence dynamic balance measures, especially in the anterior reach.89 As in the present study, similar deficits were noted in the CAI group, even though the deficits were worse than those in the AAS group.

Ankle Laxity In our study, those who have sustained an AAS still have differences in ankle laxity compared to healthy control and CAI groups, 6-months following the ankle sprain. Similarly, Croy et al.43 found that anterior drawer stress increased TI in the involved ankle (22.65 ± 3.75 mm p = .017) compared to the uninvolved ankle (19.45 ± 2.35 mm) at baseline. Inversion stress resulted in greater interval changes (23.41 ± 2.81 mm) than the uninvolved ankle (21.13 ± 2.08 mm). In a second article published by Croy et al.45, the authors identified greater length changes of the anterior talofibular

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ligament using stress ultrasonography in both coper and CAI groups compared to a control group. Significant length changes were noted in inversion (F2,57=6.5, p=.003) in the coper (20.2% ± 19.6%) and CAI (25.3% ± 15.1%) groups compared with a control group (7.4% ± 12.9%). Significant length changes were also noted in the anterior-drawer (F2,57=6.2, p=.004) in the coper (14.0% ± 15.9%, p=.016) and CAI (15.6% ± 15.1%, p=.006) groups compared with a control group (1.3% ± 10.7%). Croy et al.46 also identified 53% of subjects had anterior talocrural joint laxity at the reference standard of 2.3 mm or greater and 36% at the reference standard of 3.7 mm or greater. Previous research by Brown et al.39 concluded, comparatively, that those in the CAI group had increased mechanical laxity in inversion using an instrumented ankle arthrometer (LigMaster) compared to the control group. Even though the CAI group had significantly greater inversion laxity compared to the control group, they did not see any differences between the CAI and coper groups. Overall, the CAI to control comparison had the highest effect size (0.87), with the CAI to coper (0.49) and control to coper (0.39) comparisons at moderate to small, respectively. Mechanical laxity and stiffness may not be contributing factors of developing CAI after an initial sprain.39

ATFL Thickness

Those within the AAS and CAI groups had a thicker ATFL than CON. Musculoskeletal ultrasound has been used previously to detect the thickness at the midpoint of the ATFL in healthy, coper, and unstable ankles. Liu et al.22 examined those differences between injured limb of a coper and unstable group compared to the healthy group. The ATFL of the injured limb for the coper group (2.20 ± 0.47 mm, p = .015) and injured limb for the unstable groups (2.28 ± 0.53 mm, p = .015) were thicker

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than the ATFL of the healthy group (1.95 ± 0.29 mm). Even though, the number of previous ankle sprains does not affect the thickness of the ATFL. As an injured ligament heals, its structure and thickness may not return to the level of a healthy ligament due to the incorporation of scar tissue during healing. However, the thickness of the ligament and potential scar tissue may not increase over time or as the number of previous ankle sprains increases.

YBT Deficits in dynamic balance were noted in our study in those with CAI, specifically the ANT, PM, and COMP of the YBT. A cut-off point of 89.6% for the composite score on the YBT, has been previously identified, where a score below 89.6% was 3.5 times more likely to obtain a noncontact lower extremity injury.98 The average COMP score in CAI was 79% in the present study, which would fall in to that category of potential noncontact lower extremity injury. Asymmetry in the reach distances have been investigated previously.100,101 In the anterior reach, an observable difference > 4 cm between the limbs is associated with an elevated risk of injury.99 Our results showed < 4 cm average observable difference (ANT diff) between the limbs in all groups. (Table 5.2) Even though current research focuses heavily on the anterior reach as a risk factor, having better PL performance on the SEBT has been reported to be less likely to suffer an ankle sprain. With a SEBT PL reach under 80, participants have a 48% greater risk of suffering a sprain; however, 90% of their limb length or higher, had a significantly lower incidence of sprains.79 A potential reason for this deficit in PL reach leading to a subsequent ankle sprain, may be due to the pattern of muscle activation during this reach.79 Our results did not show a significant difference in the

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PL reach between groups; however, it was approaching significance (p = .06). Interestingly, the CAI group had an average PL reach of 87.1 % of limb length, not meeting the 90 % or higher cut off for a lower incidence of sprains. Optimal cut-off scores have been previously noted as 2, 9, and 3 cm for anterior, posteromedial, and posterolateral reach, respectively. In a previous study by Attenborough et al.113, the authors sought to identify risk factors of ankle sprains in 94 netball players. The authors noted that the PM reach in the SEBT of less than or equal to 77% of leg length increased the odds of sustaining an ankle sprain.113 Our results showed a significant difference between the groups in the PM reach; however the averages were not below

77% of leg length (99.9 ± 11.2 % AAS, 97.5 ± 14.5 % CON, 93.4 ± 12.9 % CAI, p = .042).

Ankle Function Using the IdFAI, CAIT, FAAM-ADL, and FAAM-Sport to detect ankle stability and function, AAS and CAI both had worse scores than the healthy, CON group. Previous work by Croy et al. found that the CAI group had lower FAAM- ADL

(87.4% ± 13.4%) and sports subscale (74.2% ± 17.8%) compared to the control (98.8% ± 2.9% and 98.9% ± 3.1%; respectively, p<.0001) and coper group (99.4% ± 1.8% and 94.6% ± 8.8%; respectively, p<.0001).45 Brown et al. found that self- reported function was decreased in the CAI group but not in the coper or control group. The authors connected that decreased self-reported ankle function and ankle ligament laxity may be linked.39 The International Ankle Consortium recommends that all three subjective questionnaires, CAIT114, IdFAI115,116, and FAAM117 are used to classify someone with CAI or diminished ankle function.132 It is important to

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understand that even though someone has had an initial LAS, it is even more important to monitor their ankle function over time. Previous research has also identified that those with perceived instability, have less health-related quality of life and more functional limitations compared to healthy, uninjured participants.119 Besides the potential for degenerative joint changes, those that sustain an ankle sprain may see long-term effects to their overall health if not treated appropriately.54 Recently, Hubbard-Turner et al.120 published an article on self- reported physical activity one year after an acute ankle sprain. Twenty subjects with an acute lateral ankle sprain (LAS) and 20 healthy subjects were given activity questionnaires to determine their self-reported physical activity one week before they injury compared to one year following the injury. Subjects in the LAS group scored significantly less at the one-year mark compared to one week prior (p = 0.001) and less (p = 0.02) than the healthy group at one year.

Conclusion Differences exist between the groups in range-of-motion, mechanical laxity, ATFL thickness, pain, dynamic balance, and ankle function. Those who experienced an AAS had increased laxity compared to CON and CAI. Whereas, AAS and CAI each had greater ATFL thickness than CON. Additionally, those with CAI had less range-of-motion and balance than CON. In terms of ankle function, the CAI had a greater number of previous ankle sprains and worse scores on questionnaires for ankle function and instability, than AAS and CON.

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Chapter 6

CONCLUSIONS

The overarching aim of this dissertation effort was to compare mechanical laxity, ATFL thickness and dynamic balance in a college-aged population that have experienced an acute ankle sprain by comparing them to those without a history of previous ankle sprains, in addition to those that present with subjective CAI. The primary findings were that differences exist between all groups (AAS, CON, CAI) in mechanical laxity, ATFL thickness, DFROM, and dynamic balance. Those who experienced an AAS had increased ankle laxity, a thicker ATFL, and less COMP compared to CON and CAI, 6-months following the injury. Those with CAI also had a thicker ATFL, less DFROM, less ANT reach, and less PM reach than CON. As the differences between AAS and CAI are smaller, we believe that those in the AAS group, regardless of whether they have had previous ankle sprains, will have deficits in all areas mentioned and develop CAI or worse instability down the road. It has been thought by Miklovic et al., that an acute lateral ankle sprain (LAS) leads to CAI by a pathway of dysfunction.121 This pathway is led by impairments that have been previously associated with CAI including: decreased ROM, strength, postural control, and altered movement patterns during functional activities. An impairment-based rehabilitation model has been created by Donovan and colleagues74,122 and has shown to be an effective rehabilitation strategy in those with CAI. The impairment-based model, in summary, involves assessing each potential

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impairment for the patient and determining which note deficits, then addressing the impairment through rehabilitation.122 Since similar impairments are seen in all groups, an impairment-based model may be effective for treating patients with an acute LAS.121 Recently, the International Ankle Consortium developed recommendations for clinical assessment of acute lateral ankle sprain injuries, based on expert consensus. The Rehabilitation-Oriented ASessmenT (ROAST) includes assessment the patient’s ankle in multiple areas: joint pain, magnitude of joint swelling, range-of-motion, arthrokinematics, strength, static and dynamic postural balance, gait, level of physical activity, and self-reported joint function. Along with establishing the mechanism of injury and assessment of ankle joint bones and ligaments through stress tests, clinicians need to be able to incorporate all previous areas into their assessment of acute lateral ankle sprain injuries.156,157 As our results show, deficits can be noted in those that sustain an LAS at least 6-months following the injury. As clinicians, we must implement these models into our continuing education of new and current clinicians and promote its use on every patient with an acute LAS. Each LAS may have different impairments that need to be addressed and must be reevaluated after return to full function. Ultimately, in an athletic population, current research is showing that these patients may be returning back to full participation too early, without any follow-up or maintenance rehabilitation, and may lead to incomplete recover.140 From the results of our study, differences are still noted in those with an acute LAS at 6-months following the injury. We were able to note that all of the AAS subjects had some sort of inflammation or hypoechoic area on the ligament at 6-months post-AAS with pain present (TTP). We believe that the use of

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musculoskeletal ultrasound to obtain subjective information can be important to clinicians early in those with a LAS.

Limitations While the findings of the present study offer clinicians and researchers additional insight into the long-term effects of an acute LAS, each study is not without limitation. In order to have a large enough sample, we were unable to collect a baseline test prior to the subject having the ankle sprain since the potential subject pool was very large. For the two groups used to compare against the AAS group, CON and CAI, we did not obtain additional testing sessions to coincide with the 24-72 hour and 2-4 week time points; thus, the comparison between groups was only taken at the 6-month time period. We attempted to avoid a history bias by testing the 6-month of the AAS near the time the CON and CAI were tested. In identifying those to include in the AAS group, those with previous ankle sprains on the same ankle were included. Those that had their first ankle sprain on that ankle were also included in the study. Differences may exist if those with previous ankle sprains on that ankle may have also had CAI at the time or prior to the ankle sprain occurring. History of previous ankle sprains on that ankle was used as a covariate to attempt to account for this difference. Future research may need to consider using only first time ankle sprains, if the cohort is large enough, or splitting the group into those with previous ankle sprains and those without. During the inversion and anterior drawer stress, performed by the LigMaster device, specifically at 24-72 hours following the injury, a small portion of subjects had pain during the task causing the examiner to decrease the force given to 10-12 dN instead of 15dN given standard to all other subjects. LigMaster recommended in the

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manual that decreasing to 10-12 dN133 would still reach the same results, however, there may be less stress to the injured fibers in those subjects. The majority of the subjects this occurred in suffered from a Grade II or III ankle sprain. The amount of pain that was described to the subject by the examiner prior to the test was said as “pain that is uncomfortable and unbearable that we need to stop the test for.” Also, the design of the LigMaster presented with difficulties when using on one who has a longer or shorter lower limb length (knee to ankle) and also foot size (length and width). The fit and angle in which the foot was placed into the machine varied slightly due to the subject’s size. Future research should consider measuring the subject’s lower limb length to use as a potential covariate and to determine if a relationship exists with the stress values.

Clinical Implications and Future Directions The current investigation is only of its kind to assess the long-term effects of an acute LAS, comparing to a healthy, control and CAI group. As clinicians, we must be aware that those who sustain a LAS should be assessed in the areas mentioned (range-of-motion, ankle laxity, musculoskeletal ultrasound, dynamic balance) to determine if differences exist over time, especially if the athlete has returned to play and still shows deficits in specific areas. Our results show that ankle laxity differences are noted 6-months following a LAS. The thickness of the ATFL changes and potentially alters its morphology in those with after a LAS and those with CAI. Performance in dynamic balance decline over time 6-months following a LAS; however, those with CAI have worse scores than those with a LAS. The use of MSUS and its utility for detecting a talar notch, swelling over the ligament, and potential injury to ATFL, would be extremely beneficial to health care professionals to have as

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a clinical measure after the injury and throughout the recovery phase of injury. Future research should use the methodology in the current study and further in the long-term, (1 year, 2 years, and beyond) comparing to healthy CON over time. Previous research is limited in this area of the long-term effects following a LAS and its potential for developing CAI.

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Appendix A

RESULTS FIGURES

Chapter 2 Results Figures

Girth Over Time ** 52 51.7 51.5 ** 51 50.7 50.5 50 ** 49.5

GIRTH (CM) 49.2 49 48.5 48 47.5 1 2 3

Figure A.1: Ankle Girth Over Time in AAS. (cm= centimeters, 1= 24-72 hours, 2= 2-4 weeks, 3= 6-months, **= significant differences across each group at p < .001)

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DFROM by Grade at Time 1 * 8

7 7.2

6 5.5 5

4 * 3

DFROM (degrees) 2 2.2

0 1 2 3

Figure A.2: Dorsiflexion Range-of-Motion (DFROM) by Grade (I-III) at 24-72 hours. (1= Grade I, 2= Grade II, 3= Grade III, *= significant differences between grades with p < .05)

AD/ INV Stress by Time 30

25 22.4 22.7 22.1 21.9 21.1 22.3 20

10 Stress Stress (mm) 5

0 1 2 3 Time

AD Stress, mm INV Stress, mm

Figure A.3: Anterior Drawer (AD)/ Inversion (INV) Stress Over Time in AAS. (mm= millimeters, 1= 24-72 hours, 2= 2-4 weeks, 3= 6-months)

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AD/ INV Stress by Group 30 ** ** 25 22.7 22.3 20.6 19.4 20

10 Stress Stress (mm) 5

0 AD Stress, mm INV Stress, mm AD/INV Stress

AAS (n=46) CON (n=54)

Figure A.4: Anterior Drawer (AD)/ Inversion (INV) Stress in AAS vs CON at 6-months. (mm= millimeters, AAS= acute ankle sprain, CON= control, **= significant differences between groups at p < .001)

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AD/ INV Stress by Grade at Time 1 25

24 * 23

22 * AD Stress 21 INV Stress STRESS STRESS (MM) 20 * 19

18 1 2 3

Figure A.5: Anterior Drawer (AD)/ Inversion (INV) Stress by Grade (I-III) at 24-72 hours. (mm= millimeters, 1= Grade I, 2= Grade II, 3= Grade III, *= significant differences by Grade at time 1 in INV stress at p < .05)

150

Chapter 3 Results Figures

ATFL thickness by Group at Time 3 3 ** 2.5 2.1 2 1.8

1.5

1 Thickness (MM)

0.5

0 AAS (n=46) CON (n=52)

Figure A.6: Anterior Talofibular Ligament (ATFL) Thickness in AAS vs CON at 6-months. (mm= millimeters, AAS= acute ankle sprain, CON= control, **= significant differences between groups with p < .001)

151

ATFL Thickness by Grade Over Time 3 * * 2.5

1.5

1 Thickness (mm) 0.5

0 1 2 3 Time

Grade I Grade II Grade III

Figure A.7: Anterior Talofibular Ligament (ATFL) Thickness by Grade Over Time in AAS. (mm= millimeters, AAS= acute ankle sprain, 1= 24-72 hours, 2= 2-4 weeks, 3= 6-months, *= significant differences between groups at p < .05)

152

Chapter 4 Results Figures

YBT Scores in AAS Over Time 120 * 100 ** 80

20 Relative Reach Distance (%) 0 ANT PM PL COMP

2-4 weeks 6-months

Figure A.8: Y Balance Test (YBT) Scores in AAS Over Time. (%= percentage relative to limb length, AAS= acute ankle sprain, ANT= anterior, PM= posteromedial, PL= posterolateral, COMP= composite, *= significant differences over time at p < .05, **= significant differences over time at p < .001)

153

YBT Limb Asymmetry by Group 6

5 *

3 AAS (n=46) CON (n=52) 2

Difference Score (cm/%) 1

0 ANT diff PM diff PL diff COMP diff

Figure A.9: Y Balance Test (YBT) Asymmetry Between Limbs by Group. (cm= centimeters, %= percentage relative to limb length, ANT diff= anterior difference, PM diff= posteromedial difference, PL diff= posterolateral difference, COMP diff= composite score (%) difference, AAS= acute ankle sprain, CON= control, *= significant differences between groups at p < .05)

154

Chapter 5 Results Figures

DFROM 16 * 14

12 10.6 9.9 10 8.5 8

DF ROM (degrees) 4

0 AAS (n=46) CON (n=54) CAI (n=54)

Figure A.10: Dorsiflexion Range-of-Motion (DFROM) by Group at 6-months. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, *= significant differences between CON and CAI at p < .05)

155

AD/ INV Stress by Group 23 ** 22

20 AD Stress, mm INV Stress, mm Stress Stress (mm) 19

17 AAS (n=46) CON (n=54) CAI (n=54)

Figure A.11: Anterior Drawer (AD)/ Inversion (INV) Stress by Group at 6- months. (mm= millimeters, AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, **= significant differences in AD/INV stress between AAS and CON and AAS and CAI at p < .001)

156

ATFL Thickness by Group 3 ** * 2.5 2.1 2 2 1.8

1.5

1 Thickness (mm)

0.5

0 AAS (n=46) CON (n=54) CAI (n=54)

Figure A.12: Anterior Talofibular Ligament (ATFL) Thickness by Group at 6- months. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, **= significant differences between AAS and CON at p < .001, *= significant differences between CAI and CON at p < .05)

157

Y Balance Test

* * * 100

80 * 60

Relative Reach Distance, % 20

0 ANT PM PL COMP

AAS CON CAI

Figure A.13: Y Balance Test (YBT) Scores by Group at 6-months. (%= percentage relative to limb length, AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, ANT= anterior, PM= posteromedial, PL= posterolateral, COMP= composite, *= significant differences between groups at p < .05)

158

Previous Ankle Sprains by Group * 6 * * 5

4 3.1 3 2.2 2

1 Number of Prev. Ankle Sprains 0 0 AAS CON CAI

Figure A.14: Previous Number of Lateral Ankle Sprains by Group. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, *= significant differences between groups at p < .05)

159

IdFAI 30 ** ** 25

19.2 20 16.6 15 ** Score 10

5 2.5

0 AAS CON CAI -5

Figure A.15: Identification of Functional Ankle Instability (IdFAI) by Group at 6-months. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, **= significant differences between groups at p < .001)

160

CAIT ** 35 ** 30 28.8 ** 25 23.3

20 17.1

SCore 15

0 AAS CON CAI

Figure A.16: Cumberland Ankle Instability Tool (CAIT) by Group at 6- months. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, **= significant differences between groups at p < .001)

161

FAAM-ADL * 100 90 83.5 79.3 80 73.7 70 60 50 Score 40 30 20 10 0 AAS CON CAI

Figure A.17: Foot and Ankle Ability Measure (FAAM)- Activities of Daily Living (ADL) Subscale by Group at 6-months. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, *= significant differences between CAI and AAS and CAI and CON at p < .05)

162

FAAM-Sport * * 35 31.8 * 30 27.6 25.1 25

Score 15

0 AAS CON CAI

Figure A.18: Foot and Ankle Ability Measure (FAAM)- Sport Subscale by Group at 6-months. (AAS= acute ankle sprain, CON= control, CAI= chronic ankle instability, *= significant differences between groups at p < .05)

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Appendix B

INCLUSION QUESTIONNAIRE

University of Delaware Ankle Study Inclusion Questionnaire

Subject Code Number

Age____ Height ______Weight ______Phone Number ______Email ______Sport Position

1. Have you ever sprained your ankle before? YES NO

2. If yes: which ankle? Right Left

3. Number of sprains Right: ____ Left: ____

4. Approximately- when did you last sprain your ankle? ______

5. Do you ever have episodes of your ankle “giving way” or “rolling over” during daily activity (athletic or otherwise)? YES NO

6. Have you ever fractured your ankle before? YES NO

7. Have you ever had any injuries to your knees? YES NO If yes, please explain:

8. Have you ever had surgery on any part of your lower extremities? YES NO If yes, please explain:

9. Are you currently being treated for an ankle or lower leg injury?

164

YES NO

165

Appendix C

FOOT AND ANKLE ABILITY MEASURE (FAAM)- ACTIVITIES OF DAILY LIVING AND SPORTS SUBSCALE

Online Qualtrics Surveys

Q1 FAAM Activities of Daily Living Subscale

Directions: Please answer EVERY QUESTION with ONE response that most clearly describes your condition within the past week. If the activity the question is limited by something other than your foot or ankle, mark NOT APPLICABLE (N/A).

1. Because of your foot & ankle, how much difficulty do you have with:

No Slight Moderate Extreme Unable N/A Difficulty Difficulty Difficulty Difficulty to Do (4) (6) (0) (1) (1) (2) (2) (3) (3) (4) (5)

Standing (1) o o o o o o Walking on even ground

(2) o o o o o o Walking on even ground without shoes o o o o o o (3) Walking up hills (4) o o o o o o Walking down hills (5) o o o o o o

166

Going up

stairs (6) o o o o o o Going down stairs (7) o o o o o o Walking on uneven

ground (8) o o o o o o

Stepping up and down

curbs (9) o o o o o o

Squatting (10) o o o o o o Coming up on your toes (11) o o o o o o Walking initially (12) o o o o o o Walking 5 minutes or

less (13) o o o o o o Walking approximately 10 minutes o o o o o o (14) Walking 15 minutes or

greater (15) o o o o o o

167

Q2 Directions: Please answer EVERY QUESTION with ONE response that most clearly describes your condition within the past week. If the activity the question is limited by something other than your foot or ankle, mark NOT APPLICABLE (N/A).

2. Because of your foot & ankle, how much difficulty do you have with: No Slight Moderate Extreme Unable N/A Difficulty Difficulty Difficulty Difficulty to Do (4) (6) (0) (1) (1) (2) (2) (3) (3) (4) (5) Home responsibilities

(1) o o o o o o Activities of daily living (2) o o o o o o Personal care (3) o o o o o o Light to moderate work

(standing, o o o o o o walking) (4) Heavy work (push/pulling, climbing, o o o o o o carrying) (5) Recreational activities (6) o o o o o o

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Q3 3. How would you rate your current level of function during your usual activities of daily living from 0 to 100 with 100 being your level of function prior to your foot or ankle problem and 0 being the inability to perform any of your usual daily activities? Activities of Daily Living --Level of function (Percentage) (1)

169

Q4 FAAM Sports Subscale

Running (1) o o o o o o

Jumping (2) o o o o o o

Landing (3) o o o o o o Starting & stopping

quickly (4) o o o o o o Cutting/lateral movements

(5) o o o o o o Low impact activities (6) o o o o o o Ability to perform activity with

your normal o o o o o o technique (7) Ability to participate in your desired sport as long o o o o o o as you would like (8)

170

Q5 5. How would you rate your current level of function during your sports related activities from 0 to 100 with 100 being your level of function prior to your foot or ankle problem and 0 being the inability to perform any of your usual daily activities? Sport related activity --Level of function (Percentage) (1)

Q6 Subject Number:

______

Q7 Today's date:

______

171

Appendix D

CUMBERLAND ANKLE INSTABILITY TOOL (CAIT)

Online Qualtrics Surveys

Q1 CUMBERLAND ANKLE INSTABILITY TOOL (CAIT)

Instructions: Please tick the ONE statement in EACH question that BEST describes your ankles:

1. I have pain in my ankle: Choose one answer per ankle: Running Walking Running Walking on on During on level on level Never (1) uneven uneven sport (2) surfaces surfaces surfaces surfaces (4) (6) (3) (5) Left Ankle (1) o o o o o o Right Ankle (2) o o o o o o

Q2 2. My ankle feels UNSTABLE: Choose one answer per ankle: Never (1) Sometimes Frequently Sometimes Frequently

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during sport during sport during daily during daily (not every (every time) activity (4) activity (5) time) (2) (3) Left Ankle (1) o o o o o Right Ankle (2) o o o o o

Q3 3. When I make SHARP turns, my ankle feels UNSTABLE: Choose one answer per ankle: Sometimes Often when When walking Never (1) when running running (3) (4) (2)

Left Ankle (1) o o o o

Right Ankle (2) o o o o

Q5 4. When going down the stairs my ankle feels UNSTABLE: Choose one answer per ankle: Never (1) If I go fast (2) Occasionally (3) Always (4)

Left Ankle (1) o o o o

Right Ankle (2) o o o o

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Q6 5. My ankle feels UNSTABLE when standing on ONE leg: Choose one answer per ankle: On the ball of my With my foot flat Never (1) foot (2) (3)

Left Ankle (1) o o o

Right Ankle (2) o o o

Q7 6. My ankle feels UNSTABLE when: Choose one answer per ankle: I hop from side I hop on the When I jump Never (1) to side (2) spot (3) (4)

Left Ankle (1) o o o o

Right Ankle (2) o o o o

Q8 7. My ankle feels UNSTABLE when: Choose one answer per ankle: I run on I jog on I walk on I walk on a Never (1) uneven uneven uneven flat surface surfaces (2) surfaces (3) surfaces (4) (5)

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Left Ankle (1) o o o o o Right Ankle (2) o o o o o

Q9 8. TYPICALLY, when I start to roll over (or 'twist') on my ankle I can stop it: Choose one answer per ankle: I have never Immediately Sometimes Often (2) Never (4) rolled over (1) (3) on my ankle (5) Left Ankle (1) o o o o o Right Ankle (2) o o o o o

Q10 9. Following a TYPICAL incident of my ankle rolling over, my ankle returns to 'normal': Choose one answer per ankle: I have Almost never rolled immediately < 1 day (2) 1-2 days (3) > 2 days (4) over on my (1) ankle (5)

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Left Ankle (1) o o o o o Right Ankle (2) o o o o o

Q11 Subject Number:

______

Q12 Today's date:

______

End of Block: Default Question Block

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Appendix E

IDENTIFICATION OF FUNCTIONAL ANKLE INSTABILITY (IDFAI)

Online Qualtrics Surveys Q1

IDENTIFICATION OF FUNCTIONAL ANKLE INSTABILITY (IdFAI)

Instructions: This form will be used to categorize your ankle stability status. You will complete 10 questions for the right and left ankles. Please fil out the form completely and if you have any questions, please ask the administrator. Thank you for your participation.

Please carefully read the following statement:

"Giving way" is described as a temporary uncontrollable sensation of instability or rolling over of one's ankle.

For Questions 1-10, I am completing these questions for my ______ankle. Please choose one below.

o Right (1) o Left (2)

Q2 1. Approximately how many times have you sprained your ankle?

______

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Q3 2. When was the last time you sprained your ankle?

o Never (1) o > 2 years (2) o 1-2 years (3) o 6-12 months (4) o 1-6 months (5) o < 1 month (6)

Q4 3. If you have seen an athletic trainer, physician, or healthcare provider, how did he/she categorize your most serious ankle sprain?

o Have not seen someone (1) o Mild (Grade I) (2) o Moderate (Grade II) (3) o Severe (Grade III) (4)

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Q5 4. If you have ever used crutches, or other device, due to an ankle sprain how long did you use it?

o Never used a device (1) o 1-3 days (2) o 4-7 days (3) o 1-2 weeks (4) o 2-3 weeks (5) o > 3 weeks (6)

Q6 5. When was the last time you had "giving way" in your ankle?

o Never (1) o > 2 years (2) o 1-2 years (3) o 6-12 months (4) o 1-6 months (5) o < 1 month (6)

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Q7 6. How often dos the "giving way" sensation occur in your ankle?

o Never (1) o Once a year (2) o Once a month (3) o Once a week (4) o Once a day (5)

Q8 7. Typically, when you start to roll over (or "twist") on your ankle can you stop it?

o Never rolled over (1) o Immediately (2) o Sometimes (3) o Unable to stop it (4)

Q9 8. Following a typical incident of your ankle rolling over, how soon does it return to 'normal'?

o Never rolled over (1) o Immediately (2) o < 1 day (3) o 1-2 days (4) o > 2 days (5)

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Q10 9. During "Activities of daily life" how often does your ankle feel UNSTABLE?

o Never (1) o Once a year (2) o Once a month (3) o Once a week (4) o Once a day (5)

Q12 10. During "Sport/or recreational activities" how often does your ankle feel UNSTABLE?

o Never (1) o Once a year (2) o Once a month (3) o Once a week (4) o Once a day (5)

Q13

For Questions 11-20, I am completing these questions for my ______ankle. Please choose the other ankle.

o Right (1) o Left (2)

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Q14 11. Approximately how many times have you sprained your ankle?

______

Q15 12. When was the last time you sprained your ankle?

o Never (1) o > 2 years (2) o 1-2 years (3) o 6-12 months (4) o 1-6 months (5) o < 1 month (6)

Q16 13. If you have seen an athletic trainer, physician, or healthcare provider, how did he/she categorize your most serious ankle sprain?

o Have not seen someone (1) o Mild (Grade I) (2) o Moderate (Grade II) (3) o Severe (Grade III) (4)

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Q17 14. If you have ever used crutches, or other device, due to an ankle sprain how long did you use it?

o Never used a device (1) o 1-3 days (2) o 4-7 days (3) o 1-2 weeks (4) o 2-3 weeks (5) o > 3 weeks (6)

Q18 15. When was the last time you had "giving way" in your ankle?

o Never (1) o > 2 years (2) o 1-2 years (3) o 6-12 months (4) o 1-6 months (5) o < 1 month (6)

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Q19 16. How often dos the "giving way" sensation occur in your ankle?

o Never (1) o Once a year (2) o Once a month (3) o Once a week (4) o Once a day (5)

Q20 17. Typically, when you start to roll over (or "twist") on your ankle can you stop it?

o Never rolled over (1) o Immediately (2) o Sometimes (3) o Unable to stop it (4)

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Q21 18. Following a typical incident of your ankle rolling over, how soon does it return to 'normal'?

o Never rolled over (1) o Immediately (2) o < 1 day (3) o 1-2 days (4) o > 2 days (5)

Q22 19. During "Activities of daily life" how often does your ankle feel UNSTABLE?

o Never (1) o Once a year (2) o Once a month (3) o Once a week (4) o Once a day (5)

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Q23 20. During "Sport/or recreational activities" how often does your ankle feel UNSTABLE?

o Never (1) o Once a year (2) o Once a month (3) o Once a week (4) o Once a day (5)

Q25 Subject Number:

______

Q26 Today's date:

______

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Appendix F

IRB CONSENT FORM & APPROVAL

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University of Delaware Human Subjects Informed Consent Form

RESEARCH STUDY TITLE: Ankle Injury Assessment and Tracking in an Athletic Population

INVESTIGATORS: Thomas W. Kaminski, PhD (Dept. of Kinesiology & Applied Physiology); Geoff Gustavsen, MD (UD Physician), Bethany Wisthoff (Doctoral Student Dept. of Kinesiology & Applied Physiology)

PURPOSE OF STUDY AND INTRODUCTION The purpose of this research project is to better understand factors that could lead to an ankle sprain. You are being asked to participate because you’re a student-athlete at the University of Delaware or surrounding local institutions (i.e. Wilmington University, Goldey-Beacom College, and Neumann University). You must be 18 years or older to participate in this study. We will examine different aspects of ankle function (strength, balance, looseness, ligament status, etc…) and track any changes that may occur over during your time at the University of Delaware or surrounding local institutions (i.e. Wilmington University, Goldey-Beacom College, and Neumann University). Your participation is voluntary and you are in no way obligated to take part in this project.

PROCEDURES The initial testing will take about 75 minutes to complete. You will be asked to complete a questionnaire and several tasks to evaluate your ankle. You will be asked wear workout clothing (e.g. shorts/sweatpants and t- shirt) for all testing and perform each task either barefoot or wearing running shoes. All testing will take place in the Human Performance Lab/Athletic Training Research Lab.

Questionnaire: You will be asked about your age, height, weight, and gender and will complete a questionnaire about physical activity. You will complete two questionnaires about your ankle health and past history of lower leg injuries.

Body Composition Testing: Your Lean Body Mass (LBM) will be determined using a device called a Bod Pod®. Wearing a pair of shorts, you will sit in the device, which is a small egg shaped apparatus with a window. You will remain quiet, still and breathe normally for about 10 minutes. During this time, the device makes a series of calculations based on your weight.

Strength Testing: Ankle strength will be measured using an isokinetic dynamometer; a device that you will sit on that easily measures ankle force. Strength measurements will be performed on both ankles at a slow and fast speed for all four ankle motions (up, down, in, and out). You will wear running shoes during this test and will perform 3 warm-up reps followed by 3 maximal repetitions at each speed and motion (see image below).

I nitial UD IRB Approval from 08/27/2018 to 08/25/2019

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Stability: You will be asked to perform hopping tasks onto a force platform built into the floor. The four hopping tasks will be from the left, right, backward, and forward directions. For the left, right, and backward hopping tasks, you will be standing next to the force platform, single-legged and barefoot, and have your hands on your waist. After you hear the command “go”, you will hop over a 2” hurdle to the center of the force platform. Your task is to stabilize yourself as quickly as possible (see image below). You will hold the position for 5 sec. This procedure will be repeated using the other foot. For the forward hops, we will measure your leg length (from hip to ankle) and place a rubber hurdle 6” high between you and the force platform. We will demonstrate the “step-step-hop” method to hop over the rubber hurdle. You are to land one-footed on the force platform (barefoot), and again stabilize for 5 sec. You will perform this procedure separately on both the left and right foot. You will be asked to perform three trials of each hopping task.

Balance Assessment (using the Balance Error Scoring System (BESS)

We will assess your balance while standing quietly on either a firm or foam surface using the three stances shown above. Balance will be evaluated using the Tekscan MobileMat™ BESS while the mat surface shown above is connected to a laptop computer which performs all scoring. You are to remain as motionless as possible during each test trial. Each trial is timed for 20 sec. You will perform one trial of each stance in your bare feet.

Balance Assessment (using the Y-Balance Test)

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Post-Acute Ankle Injury Follow-Up Testing: In addition to the above mentioned injury tracking; following any acute ankle sprains we intend to perform these post-injury tests (described above) at multiple time points (24 hr., 2-4 weeks, 3 months, 6 months, 1 year, and 2 years) over the course of their athletic career at the discretion of the university medical staff: 1) Questionnaires 2) Strength Testing

3) Stability 4) Balance Assessments (Y-Balance & BESS) 5) Ankle Arthrometer 6) Ultrasound Imaging

CONDITIONS OF SUBJECT PARTICIPATION All the data will be kept confidential. Aggregate (cumulative) data from this study will be shared with the sports medicine or student health center staff at the University. In addition, records of any athletic- related injuries that you experience while participating as a student-athlete will be shared with the research team. Your information will be assigned a code number. The list connecting your name to the code number will be kept in a locked file. When the study is completed and the data have been analyzed, that list will be destroyed, but the coded data will be kept indefinitely on a secured electronic file device. Your name will not be used in conjunction with this study. In the event of physical injury during participation, you will receive first aid. If you require additional medical treatment, you will be responsible for the cost. You will be removed from the study if you experience any injury that interferes with the results or prevents you from completing it. There are no consequences for withdrawing from the study and you can do so at any time. RISKS AND BENEFITS Potential risks in this project are minimal. As with any exercise or challenging movements, risks include fatigue, localized muscle soreness, and the potential for strains and sprains of muscles and joints of the lower leg. There is a slight risk to you of suffering bone, muscle, or joint injuries during the exercise protocol. If you are injured during research procedures, you will be offered first aid at no cost to you. If you need additional medical treatment, the cost of this treatment will be your responsibility or that of your third-party payer (for example, your health insurance). By signing this document you are not waiving any rights that you may have if injury was the result of negligence of the university or its investigators. If you become too fatigued or uncomfortable, you may stop the test at any time. Potential benefits include the better understanding of why some people sprain their ankle more than others. In addition, this study can lead to identify predisposing factors to an ankle injury and therefore help prevent future ankle injuries.

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CONTACTS Questions regarding the research study can be directed to Dr. Thomas W. Kaminski (302) 831-6402 or [email protected]. For questions of concerns about the rights to the individuals who agree to participate in the study: Human Subjects Review Board, University of Delaware (302) 831-2137.

ASSURANCE Participation in this study is completely voluntary. You may stop at any time during the testing without penalty. Refusal or choosing to discontinue participation in this study is the right of the individual, with no loss of benefits to which the subject is otherwise entitled.

CONSENT SIGNATURES

Subject Consent Signature Date

Principal Investigator Signature Date

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